biology 1- 8

chapter 5 - communicable diseases

chapter 3 - digestive system

chapter 1 - cells and organisation

chapter 7 - non commnicable diseases

chapter 6 - preventing and treating disease

chapter 4 - animals and plants

chapter 8 - photosynthesis

chapter 2 - cell division

microscopes
magnification = size of image / size of real object
1000 micrometres to a millimetre
light microscope - cheap, used almost anywhere, beam of light to form image of objectand can magnify thinsg several 100 times.
electron microscope - use beam of electrons to form and magnify image, can magnify up to around 2 million times.
transmission electron - 2d, higher magnification
scanning electron - 3d, lower magnifications

animal and plant cells
plant cells have cell walls and chloroplasts
animal cells dont. otherwise they have the same for everything.
nucleus : controls activities and contains DNA
cytoplasm: liquid inside cell where most of chemical reactions happen
cell membrane : keeps things together and controls what enters and leaves
mitochondria : where aerobic respiration happens and releases energy from food
ribosomes : where protein synthesis takes place
chloroplasts : absors light for photosynthesis and to make food
permanent vacuole : filled with sap
cell wall : strengthens the cell

eukaryotic and prokaryotic cells
all bacteria are prokaryotes
eukaryotes - cell membrane , cytoplasm and nucleus
prokaryotes - cytoplasm, cell membrane and cell wall

specialisation (animal)
mainly happens in embryos, specialise early in development, mature animals , cells mostly divide to repair tissues and replace cells.

  • sperm cells
    head( contains one half of genetic material to be paired with the egg's half), middle (contains mitochondria for energy) and tail (flagella to allow it to move toward egg) main purpose is to fertilise egg cells
  • muscle cells
    contains lots of mitochondria for energy and protein fibres to contract the muscles, allowing them to move.
  • nerve cells
    specialised to transmit electrical messages around the body

osmosis
osmosis - water moviving from dilute to concentrated solution
hypotonic - draw water into cells - red cells swell up and burst
hypertonic - draw water out of cells - plant cells shrivel up.
isotomic - solute concentration is teh same inside and outside of cell so no net diffusion of water.

specialisation (plant) happens throughout their lives

  • root hair cell
    no chloroplasts because under ground so don't need to photosynthesise
    have long projections to increase sa of plant to absorb more water and minerals.
  • xylem vessels
    made up of connected dead xylem cells
    end wall are broken so water can pass through
    lignin strengthens the cell walls
  • phloem
    end of walls of phloem cellscontain small holes to allow food move up and down the plant
    transport food products

diffusion movement of a substace from an area of high to low concentration
if the difference of concentration is big, the diffusion happens quickly, if it is small, it happens slower.

active transport
opposite of diffusion
low to high concentration
cells move against concentration gradient
cells absorb ions from very dilute solutions
takes breakdown of ATP to povide energy for active transport system to carry molecule accross membrane then returns to origina position.
happens when glucose concentration is outside the cell not inside.
energy from respiration and transport proteins.

exchanging materials
surface area = (lengthxheight)x6 (SA)
volume = lengthxheightxwidth
as size increases, SA to volume ratio decreases.

cell division
CELL CYCLE : stage 1 - interphase chromosomes are copied, longest stage, replicates dna
stage 2 - mitosis the nucleus divides into 2 stage 3 - cytokinesis the membrane splits the cells into 2. forms 2 genetically identical cells. called daughter cells.

growth and differentiation
differentiation is when young cells take on characteristics and reach individual form and function.
when cells specialize
animal cells can only differentiate once in their lives - through specialization.
most plant cells can change throughout their lives whenever they are needed.
growth is a permanant increase in size as a result of cell division or enlargment.

stem cells + dilemmas
stem cells - the 1st cell in the embryo that then differentiates to create different cells. some stem cells remain even as adult.
there are some researches that say that stem cells can be use to regenerate cells that no longer work to cure certain diseases.the oly problem is hat embryotic cells could cause cancer if used in people so might not work.
at the moment research is being conducted to potentially cure : spinal cord after injuries, diabetes, heart after a heart attack, eyesight after blindness and damaged bone and cartillage.

tissue and organs

  • cells - basic building blocks of all living organisms.
  • tissue - group of cells with similar structure and function
  • organ - aggregations of tissues performing specific functions
  • organ system - organs put together to work together and make organisms
  • organisms - a living thing
    TYPES OF TISSUES -
  • epithelial : lines body, surfaces, lines, cavities and ducts
  • muscle : contracts and relaxes itself to move other body parts
  • connective : blood, bone, fat and cartilage
  • nerve : carries signals from brain and spinal cord to everywhere else.

human digestive system

  • mouth - where the food enters the alimentary canal and digestion begins
  • salivary glands - produce saliva containing amylase
  • oesophagus - muscular tube which moves ingested food to the stomach
  • stomach - muscular organ where digestion continues.
  • pancreas - produces digestive enzymes
  • liver - produces bile
  • gall bladder - stores bile before releasing it to the abdomen
  • small intestine
    • duodenum - where food is mixed with digestive enzymes and bile
    • iteum - where the digested food is absorbed into blood and the lymph
  • large intestine -
    • colon - where water is reabsorbed
    • rectum - where faeces are stored
  • anus - where faeces leave the alimentary canal
  • chemistry of food
  • carbohydrates :
    • made up of units of sugars
    • contain carbon hydrogen and oxygen
    • provide fuel for reactions
    • they are energy stores
      • all sugar molecules
  • lipids :
    • fats and oils
    • energy store in body and energy source in diet
    • made of glycerol and fatty acids
    • very important in cell membranes, hormones and nervous systems.
    • made of carbon hydrogen and oxygen
    • insoluble in water
    • lipid rich food include butter all oils cheese and cream
      • all fatty acids but one glycerol molecule
  • proteins :
    • structural components of tissue muscles and tendons
    • hormones ; insulin
    • antibodies which destroy pathogens as part of immune system
    • some proteins found in cheese, meat, milk, rice
    • easily broken and sensitive to heat and pH
    • made up of nitrogen, hydrogen and oxygen
      • all amino acids

catalysts and enzymes

  • catalysts : substances that increase the rate of chemical reactions without being used up
  • enzymes : biological catalysts. are protein molecules and are made up of amino acids. most contain between 100 and 1000 amino acids.
  • enzyme + substance <--> enzyme substrate complex <--> enzyme + product
  • dont change a reaction
  • make them happen faster
  • metabolism : all reactions in one cell body
  • all controled by enzymes
  • 100 or more in each cell
  • each reaction controlled by specific enzyme
    • type of reactions :
      • build larger molecules from smaller ones e.g. glucose from carbon dioxide and water
      • change one molecule into another e.g. glucose into fructose
      • breakdown large molecules into small ones e.g. proteins carbohydrates and lipids during digestion
  • inorganic catalysts work faster than organic ones

factors - enzyme action
pH, temperature and concentration affect the enzyme. if it doesn't have the right factors, it will not be able to bind to the substance and will not be able to help it.

how system works
digestion - where enzymes break down large insoluble molecules in food into smaller soluble molecules that are absorbed in the small intestine
ENZYMES

  • carbohydrates : made in salivary glands, turns starch into sugars or glucose, in the mouth and small intestine.
  • lipase : made in pancreas and small intestine, breaks down lipids into fatty acids and glycerol, in the small intestine
  • protease : made in stomach, pancreas and small intestine, breaks down proteins into amino acids, in the stomach

efficient digestion if at proper temperature (body temp), optimum ph, a high concentration and a large surface area enzymes work quickly and efficiently for your body.

photosynthesis when co2 and water are coverted to glucose and oxygen
some of teh glucose is used immediately fr respiration and the rest is stored by being converted to soluble starch but can be conveted back to glucose when needed.
at night or when there is no sun plants need the storage
takes place in teh green parts where there is sun.
chloroplasts absorb light for photosynthesis
energy transferred from environment to chloroplasts by light
byproduct (oxygen) released into air for us to breathe
368,000,000,000 tonnes oxygen released every year.
endothermic reaction
needs input of energy from environment.

rate
INVERSE SQUARE LAW
as distance from plant increases, light intensity decreases.
light intensity = 1/distance^2

how plants make glucose plants take water and co2 and convert it into glucose
equation :
6CO2 + 6H2O ----> C6H12O6 + 6O2
carbon dioxide + water = glucose + oxygen

making most of the photosynthesis using greehouse growing :

  • control limiting factors to maximise the photosynthesis
  • plants will grow as quickly as possible
  • even growth in water to balance nutrients perfectly (hydroponics)
  • computer controlled
    costs a lot of money but profits are high.

cancer
tumour forms during uncontrolled cell cycle
BENIGN tumour :
cells contained in one place usually in membrane. non invasive, do not go anywhere else
get very big very quickly
can be life threatening if in brain because of size
MALIGNANT tumour :
cancerous and invasive
if not treated will grow in other organs
divide quickly, live longer.
split up, sending out clumps of cells into blood then circulate and get stuck, causing more tumours (secondary tumours)
deadly and difficult to treat
CAUSES
genetic risk factors - breast and ovarian
mutations - changes in genetic material
carcinogens - cancer causing agents (chemicals - abestos or tar)
ionising radiation - uv light + xrays that interrupt cell cycle
viruses - cervical (hvp)
TREATING
radiotherapy - cells destroyed by radiation, stops mitosis in cancer and normal cells
chemotherapy - chemicals used to stop cancer cells dividing or make them self destruct.

smoking

  • NICOTINE = addictive but relatively harmless, sensation of calm, well-being and being able to cope - why people smoke
  • CARBON MONOXIDE = poisonous gas, reduces oxygen carrying capacity of blood, leads to breathlessness
  • PREGNANCY
    oxygen shortage in pregnant women who smoke, both women and fetus need oxygen, fetus might not grow properly
    premature birth, low birth weight, still birth (3500 per year - 700 due to smoking )
  • CARCINOGENS
    chemicals in tobacco smoke anaesthetise cilia in trachea and bronchi so they stop working and lets dirt and pathogens into lungs - higher risk of infection
    mucus builds up and causes coughing
    tar - sticky black accumulates in lungs and causes bronchitis, chronic obstructive pulmonary disease (copd)
    SA:V ratio reduced leading to severe breathlessness and death
    carcinogens - lung, trachea, larynx and throat cancer
  • HEART AND BLOOD VESSELS
    chemicals in tobacco affect them
    casual mechanism not just correlation: narrows blood vessels in skin (ageing it), nicotine increases heart rate, other chemicals damage lining of arteries, coronary heart disease and clot formation, high blood pressure and heart attacks and strokes.

diet and exercise

  • if you eat more food than needed = you are malnourished, excess stored as fat, some useful - cushion organs and energy store
    overtime becomes overweight and obese
  • OBESITY = heavy accumulation of fa on you body to such a degree that it increase risk of diseases that damage health
  • PROBLEMS WITH OBESITY = arthritus, diabetes, high blood pressure, heart disease, breathlessness
    excercise and health -
    food transfers energy to muscles for respiration
    more excersize more respiration
    more exercise = fitter + bigger muscles (up to 40%), fitter hearts and bigger lungs
    muscles need more energy from food.
    food intake
    60-75% to keep you alive
    10% to digest food
    15-30% affected by levels of physical activity
  • CAUSAL MECHANISM
    more muscle = high metabolic rate so less likely to be overweight
    fitter heart with better blood supply
    lower cholesterol levels/balance
    lower risk of fatty deposits in coronary arteries- reduces heart attack risk
  • TYPE 2 DIABETES
    not enough insulin made or cells stop reacting to it
    problems with circulation, kidney function, eyesight, and death
    more common with old age, genetic tendency, overweight/obese people, and those who don't excercise
    by 2025 estimated about 4 million people willl have diabetes (90% type 2)
    to restore normal blood glucose balance by having balanced diet, limited carbohydrates, losing wight + regular excercise.

alcohol and other carcinogens ethanol - very toxic and addictive
removed by liver
passes from gut --> blood --> brain
affects nervous system - thoughts reflexes and reactions slower
sometimes makesyou happy
leads to lack of self control and judgement
too much deadly
liver damage
cirrhosis destroys liver tissue
alcohol is carcinogen, spreads quickly and is difficult to treat
causes brain to become soft and pulpy
structures lost can lead to death
usually takes years to be detected.
PREGNANCY
miscarriage, still birth, premature, low birth weight.
foetal alcohol syndrome = facial deformity, teeth, hearing, kidneys, liver and heart problems, learning and development problems,
the more you drink the more risky it is for the unborn child
IONISING RADIATION
electromagnetic waves and radioactive materials penetrate cells and damage chromosomes and cause mutations in dna
the more you are exposed to them the more likeley you are to have cancer.
ultarviolet from the sun - skin cancer
radioactive substances in soil water and air
medical and dental xrays
accidents and nuclear power generators e.g chernobyl

monoclonal antibodies

  • Monoclonal antibodies are produced from clones (genetically identical copies) of cells (often white blood cells). They are all identical and are complementary to one type of antigen (proteins found on the surface of pathogens).
    they target specific chemicals or cells in the body.
  • used to treat diseases, e.g. cancer. can attach anti cancer cells to monoclonal antibodies so they deliver teh drugs directly to the tumour. effective as they cant harm body cells
  • pregnant women have a hormone called HCG, the monoclonal antibodies can bind to it so if it is detected in the pee, the antibodies bind and show the pregnancy but if none are detected, there is a negative result.
  • they can identify chemicals in blood. they can bind specific molecules with fluorescent die. if theres a lot of those molecules in one area , the dye will make them stand out.
    they can also identify levels of hormones in blood and to test blood samples e.g. for HIV.

discovering drugs

  • traditional medicines extracted form plants e.g digitalis and diagoxin extracted from foxglove(used to strengthen heartbeat but can be deadly in large amounts.) and aspirin from willow bark(anti inflamatory and pain releiving.)
  • penicilin discovered by alexander flemming who left a plate agar plate over 2 weeks and mould got into it and something in it killed bacteria. he gave up as he could not mass produce. 11 years later chain and florey mass produced, and was finally done by an american company. saved lots of soldiers in the war. often called miracle drug as fixes meningitis, gonorrhoea, scarlet fever and etc.
  • companies often use computer modelling to find new compounds which are often finding a new plant or microbe e.g. the noni fruit in costa rica with antibiotic properties.

antibiotics and painkiller

  • analgesic (painkiller) like aspirin and paracetamol releive pain but do not kill pathogens.
  • antibiotic like penisiln and arithmicin kill bacteria but wont make you feel better. kill bacteria pathogens without damaging body cells.
  • neither can kill viral pathogen, have no effect on disease.
  • some mutations - genetically changed bacteria - is resistant to antibiotics
  • to reduce antbiotic resistance, we can not overuse antibiotics, not using them to treat viruses, finishing courses of antibiotics so no bacteria survive and mutate.

vaccination -

  • white blood cells create lymphocytes that create antibodies and antitoxins. and phagocytes that create phagocytosis. (that engulf things. )
    how they work :

  • harmless pathogens are injected, antigens trigger an immune response. can take days for the lymphocyte making complementary antibodies to be activated, lymphocyte able to make them multiplies, antibodies released, memory cells that last years are produced for long term immunity.


  • when antigens from a pathogen get into us it triggers the white blood cells to either create phagocytes to engulf them or lymphocytes to create antibodies to destroy them. later the body will recognise the antigens and be ready to repel them before they can make us ill. we are immune.

making monoclonal antibodies A mouse is injected with the chosen antigen (obtained from a pathogen). The mouse’s immune system responds by producing lymphocytes (white blood cells) that produce the particular antibodies against that antigen. The lymphocytes are extracted from the mouse and fused (combined) with myeloma cells (tumour cells) to form hybridoma cells. The myeloma (tumour) cells grow rapidly and lots of identical cells are produced. All of the hybridoma cells produce the same antibody. These monoclonal antibodies are collected, purified and can then be used to target specific cells and chemicals.

developing drugs

  • making of drugs
  1. drug discovery - 4.5 years
  2. preclinical testing - tested on animals for toxicity - 1.5 years
  3. tested on human volunteers - healthy patients check for side effects - 1.5 years
  4. tested on patients - check for efficacy and dosage
  5. double tested trials - real medicine and placebo (identical but doesnt contain the drug) given to patients. only scientists know which is which, patients and dctors dont.
  6. checked by NICE ()national institute for clinical excellence.) medical journals checked and approved
  7. liscened and prescribed - 1.5 years

heart
muscular organ that pumps blood around body.
4 chambers : right and left atrium and right and left ventricles. also contains valves and a pacemaker. left atrium is on left of body.
has a DOUBLE CIRCULATORY SYSTEM

  1. deoxygenated blood from the body enters right atrium.
  2. de-oxygenated blood pumped out of heart towards lungs by right ventricle
  3. at the lungs, de-oxygenated blood exchanges carbon dioxide for oxygen, becoming oxygenated.
  4. oxygenated blood returns to left atrium of heart
  5. oxygenated blood is then pumped around teh body, losing all oxygen and being replaced with co2 then returning to the heart.

transpiration

  • factors affecting rate
    • increased temp - molecules move faster, evaporation and diffusion faster.
    • increased air movement - removes water vapour around leaf increasing concentration gradient so diffusion faster
    • increased light - opens stomata so co2 mves faster for photosynthesis, so water vapour evaporates faster.
    • reduced humidity - lower water vapour concentration arond leaf diffusion faster.
  • adaptations to reduce water loss :
    • waxy cuticle - creates waterproof layer so water doesnt get through
    • stomata under leaf - protects them from direct light and energy of sun.
    • wilting - protection mechanism against further water loss. leaves hand down and collapse - reducing surface area available for evaporation.
    • stomata close - stops photosynthesis and risks overheating but prevents most water loss and further wilting.

blood vessels

  • ARTERIES: carry blood away from heart to organs, have no valves, small lumen and contain thick elastic fibres and muscles.
  • CAPILLARIES: link arteries and veins, has very thin walls, no valves and narrow lumen.
  • VEINS: carry blood towards heart away from organs, often have valves(thinner walls) to prevent back flow. large lumen.

blood
components:

  • red blood cells : carry oxygen from lungs to rest of body
  • white blood cells : help fight infections and aid immune process.
  • platelets : fragments of cells that help blood from clotting to create scabs

helping the heart

  • leaky valves : valves prevent back flow of blood, over time they may start to leak or become stiff and hat can lead to breathlessness and eventually death. can be replaced by mechanical (titanium and polymer) valves or biological (pig, cattle or human) valves. mechanical valves good as last a long time but you have to take medication whole life to stop blood from clotting. biological good as well as no medication but only last 12-15 years and work really well.
  • rhythm problems : natural pacemaker in right atrium controls rhythm of heart. if becomes faulty heart will beat to slow or quick. Artifical pacemakers(electrical device which is attached to heat by wires) fitted to correct irregularities.
  • heart failure : sometimes heart fails completely and needs replacement from a donor where just heart or lungs as well are transported. artificial hearts are being developed but are a temporary solution.

breathing and gas exchange alveolus have a moist surface to make diffusion easy, epithelial cells, red blood cells that carry is breathed in oxygen and is breathed out carbon dioxide because the oxygen goes into the blood, to the brain, then back as carbon dioxide. in and out of blood by diffusion. spherical shape for more surface area.

tissues and organs in plants

  • fruit : protects the seed and aids its dispersal
  • flower : the reproductive organ of the plant, produces seeds.
  • leaves : contains chloroplasts so photosynthesises.
  • stems : supports the leaves and flower and has transport systems
  • roots : absorbs water and minerals from the soil

transport systems in plants

  • xylem vessels


    made up of connected dead xylem cells


    end wall are broken so water and mineral ions can pass through


    lignin strengthens the cell walls


    gives plant support


  • phloem


    end of walls of phloem cells contain small holes to allow food move up and down the plant


    transport food products


    living


    translocation

  • make glucose by photosynthesis in teh green parts
    glucose needed all over plant
    water and mineral ions from soil to every cell of the plant.

pathogens and disease
communicable diseases spread by microorganisms called pathogens which include bateria, viruses, fungi and protists
bacteria and viruses reproduce inside your body: viruses in cells bacteria release toxins to make you ill.
how they are spread :

  • coughing and sneezing (airborne pathogens)
  • contact (direct skin - sexual, indirect - surfaces)
  • vectors (flies, dogs)
  • food and water (salmonella)
    examples :
    viruses - fly, colds, measles, mumps, rubella, chicken pox, aids
    fungi - rose black spot, thrush
    protists - malaria
    bacteria - gonorrhea, typhoid, cholera, food poisoning

growing bacteria in the lab

  • grow microorganisms to find out :
    • what nutrients it needs to grow
    • how to kill it best
    • if we can make food with it
  • to prepare for an uncontaminated culture:
    • sterilise petri dishes with an autoclave
    • sterilise inoculating loops by burning them on bunsen burner
    • dont breathe on it
    • close lid asap

health and disease
health = state of physical and mental well being
disease = condition in which body is not woking correctly
how health problems interact :
viruses can cause cancer
defects in immune system can make infectious diseases more likeley
immune reactions to pathogens can cause allergies
physical ill health can lead to mental ill healh
malnutrition can lead to disease.

prevential bacteria growth

  • raise or lower temperature
  • use disenfectant to stop bacteria in an environment
  • use antiseptic to stop bacteria on our skin
  • use antbiotics to stop bacteria inside our bodies

preventing infections

viral diseases
facts :
cant replicate without a host but can exist on surfaces longer than bacteria
many virus infections don't cause symptoms
not alive
10 to 100 x smaller than bacteria
difficult to treat
more deadly than bacteria
antiviral dont kill them, only prevent viral replication
replicate and evolve faster than bacteria
are proteins
nb vaccinations protect against them
examples :

  • measles : transmitted through inhaling sneezed droplets, cause fever, sore eyes, runny nose, small white spots inside mouth, harsh dry cough, going off food, tiredness, pain and aches. no specific treatment other than avoid contact but usually heals withing 7-10 days
  • HIV : trasmitted through unprotected sex, drugs, birth, working in healthcare, breast feeding, injecting blood, blood transfussion. symproms arebody rash, fever, sore throat,immne system stops working. treated by antirevitoral drugs.
  • tobbaco mosaic virus : transmitted through contact and insect vectors. symptoms are pattern of discolouration on leaves, stunted growth, no treatment (plant disease)

plant defence responses.

bacterial diseases
facts :
can live on its own
can die if not in proper conditions
size varies between 0.2 and 10.0 micrometres in diametre
killed by antibiotics
examples :

  • salmonella : transmitted by eating contaminated poultry foods like chicken or eggs. symptoms are fever, abdominal pain, diarrea and vomiting. treaments are antibiotics if necessary
  • gonorrhoea : transmitted by unprotected sex, symptoms are thick yellow discharge from penis or vagina and pain from urination, infertility. treatments are antibiotics and use condoms
  • Agrobacterium tumefaciens : spread through contact, symptoms are crown galls (mass of tumour cells), no treatment as it is wideley used to genetically modify plants

fungi and protist diseases.
fungi = yeast, mushrooms and toadstools, athletes foot, rose black spot
protist = ameoba, algae, seaweed, plasmodium (malaria)
ROSE BLACK SPOT

  • caused by fungi
  • purple or black spots on leaves which turn yellow and drop early
  • affects growth as photosynthesis reduced
  • spread by water or wind
  • treated by fungicides and or removing and destroying affected leaves
    MALARIA
  • spread by female anopheles mosquitos that ite humans to get blood to lay her eggs
  • when she bites human, spits into bloodstream spreading plasmodium
  • when plasmodium reproduces asexually in the liver and red blood cells
  • leads to fever shaking and weakness
    660,000 people die globally each year
    drugs to treat t many pathogens are esistant though
    can be prevented:
    insectides and insect nests, vaccines, remove stagnant water and drugs for travellers

human defence responses

how a virus invades a cell :

  1. enters cell
  2. substances in cell begin stripping off viruses outer coat of protein
  3. nucleic acid in center of virus released
  4. nucleic acid gets into cells chemical manufacturing system
  5. cell "ignores its own needs" and starts making new viruses
  6. cell is sometimes destroyed in the process, many of thew viruses released to infect other cells.

biology 9 - 16

chapter 9 - respiration

chapter 10 - human nervous system

chapter 11 - hormonal coordination

chapter 12 - homeostatis in action

click to edit

click to edit

click to edit

click to edit

aerobic respiration
reactants : glucose and oxygen
products : water, carbon dioxide and energy
word equation = glucose + oxygen --> water (+energy) + CO2
C6H12O6 + 6O2 --> 6H2O (+energy) + 6CO2
in the cell it takes place in the mitochondria
its is an exothermic reaction - releases thermal energy , this is because the energy released is greater than the energy used.
living things use aerobic respiration to grow, develop, reproduce or do anything.


bicrbonate indicator is used to see if aerobic respiration takes place. when there is lots of carbon dioxide it is yellow, at the middle ground it is red/orange and with no carbon dioxide it is purple/blue.

response to exercise
when you exercise, your heart rate accelerates your breathing gets faster and heavier and your breathing volume increases. everything increases because more oxygen is needed around the body.
pulse :
radial pulse - wrist
carotid pulse - neck.

anaerobic respiration anaerobic respiration is less efficient than aerobic respiration as aerobic uses 2900 kj more energy than anaerobic. this is because the glucose molecules are not broken down completely so far less energy is consumed.
lactic acid still contains a lot of energy.
glucose --(+energy)--> lactic acid.
C6H12O6 ---> 2C3H6O3 (+energy)
oxygen debt
the waste lactic acid you produce during anaerobic respiration is a problem, it cant be breathed out like CO2
as a result when the exxcersise is over the excess lactic acid has to be broken down into carbon dioxide and water.
this requires oxygen
the amount of oxygen required to break down the lactic acid is called oxygen debt
your heart rate and breathing remain high until you have paid off the debt
the bigger the debt the longer you are out of breath.
plants and microorganisms
plants do not form lactic acid. they frm ethanol and carbon dioxide
microorganisms can make lactic acid, e.g. bacteria can make yogurt
yeast can make CO2 and ethanol (C2H5OH)
anaerobic respiration in yeast is called fermentation : the word equation is
glucose ---> ethanol + carbon dioxide
C6H12O6 ---> 2C2H5OH + CO2


muscle fatigue is inefficient muscle contraction caused by built up lactic acid.
oxygen debt is he vlume of oxygen needed to break down lactic acid
anaerobic respiration is the breakdown of glucose to release energy WITHOUT oxygen
aerobic respiration is the breakdown of glucose to release energy WITH oxygen

metabolism and the liver -
the liver and alcohol :
too much alcohol = liver disease because thanol in alcohol is a toxin so the liver works hard to get rid of it and over time it causes scarring + sorosis
metabolism :
metabolism is all chemical reactions hat go on inside the body or a cell
metabolic reactions are controlled by the presence or absence of enzymes that act like catalysts
a cell gets the energy needed fr metabolism from respiration.
metabolism either the build up of new molecules or the breakdown of larger molecules.
ANABOLIC - metabolic reactions that build new molecules (building enzymes, fat for storage, glucose as glycogen)
CATABOLIC - metabolic reactions that break down larger molecules (resiration of sugars, digestion, breaking down glycogen into glucose)
deamination = getting rid of the amino group (a part of a molecule)
each protein is made up f a chain of molecules called amino acids. there are 20 of them.
there is also a variable group which is different for each molecule.
when a protein is not needed anymore (when a cell dies) parts its made are recycled in the liver.
deamination is one stage.
the process of deamination turns the group into ammonia which is toxic, then it is gotten rid of by being turned into a chemical called urea.
urea dissolves into the blood but it is poisonous too, so we get rid of it by filtering the blood through the kidneys which extract the urea and turns it into urine. it passes through the kidneys to our bladder where it is stored until urination.