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Biology - Coggle Diagram
Biology
Gas Exchange
Ventilation
The exchange of air between the atmosphere and the lungs - achieved by the physical act of breathing
The exchange of oxygen and carbon dioxide between the alveoli and bloodstream (via passive diffusion)
Cell respiration
The release of energy (ATP) from organic molecules.
Respiratory system
Air enters through the nose or mouth and passes through the pharynx to the trachea
Air travels down the trachea until it divides into two bronchi (singular: bronchus) which connect to the lungs
The right lung is composed of three lobes, while the left lung is only comprised of two (smaller due to position of heart)
Inside each lung, the bronchi divide into many smaller airways called bronchioles, greatly increasing surface area
Each bronchiole terminates with a cluster of air sacs called alveoli, where gas exchange with the bloodstream occurs
Cellular Respiration
Glucose + Oxygen -> Carbon Dioxide + Water + Energy
Glycolysis - the breakdown of glucose by enzymes, releasing energy and pyruvate (oxygen not needed)
Homeostasis
What is Metabolism?
The chemical processes that occur within a living organism in order to maintain life.
There are 2 types of chemical reactions: Anabolic, and Catabolic
Intro to Homeostasis
Our body has preferences for temperature, pH (acidity), oxygen levels, and many other factors in order to survive.
Chemical reactions
Enzymes are proteins that act as a biological catalyst in your body, and require certain conditions to work effectively.
What is homeostasis?
A state of equilibrium or balance inside an organism that all body systems work together to maintain.
Digestive Systems
The body requires energy to survive, energy such as carbohydrates, sugar, starch are broken down to glucose by the digestive system.
Turn food into energy needed to survive, and to defecate bodily waste and residue from the body.
This energy is transferred into glucose which is then sent immediately to other organs or stored in the liver as glycogen.
Many components of the digestive system each with slightly different tasks as nutrients are absorbed from food and drinks.
The 2 major groups of organs
Alimentary Canal
The organs which foods pass through
Oesophagus
stomach
small & large intestine
Accessory Organs
Aid in digestion but food doesn’t pass through
Salivary gland
Pancreas
Liver
Gall Bladder
Parts of the digestive system
Small Intestine
A long, highly folded tube where usable food substances (nutrients) are absorbed
Consists of three sections – the duodenum, jejunum and ileum
Microvilli
Tiny hair-like projections in small intestine.
Increase the surface area of the small intestine
Allow more nutrients absorbed
Large Intestine
The final section of the alimentary canal, where water and dissolved minerals (i.e. ions) are absorbed
Consists of the ascending / transverse / descending / sigmoid colon, as well as the rectum
Stomach
A temporary storage tank where food is mixed by churning and protein digestion begins
It is lined by gastric pits that release digestive juices, which create an acidic environment (pH ~2)
Salivary Glands
It releases saliva to moisten food and contains enzymes (e.g amylase) to initiate starch breakdown
Oesophagus
A hollow tube
connect the oral cavity to the stomach (separated from the trachea by the epiglottis)
Food is mixed with saliva and then is moved in a bolus via the action of peristalsis
Pancreas
It produces a broad spectrum of enzymes that are released into the small intestines via the duodenum
It also secretes hormones (insulin, glucagon), which regulate blood sugar concentrations
Liver
Takes the raw materials absorbed by the small intestine and uses them to make key chemicals
Its role includes: detoxification, storage, metabolism, bile production, and haemoglobin breakdown
Gall Bladder
It stores the bile produced by the liver (bile salts are used to emulsify fats)
Bile stored in the gall bladder is released into the small intestine via the common bile duct
Photosynthesis
Carbon Dioxide (6CO2) + Water (6H2O) -> Glucose (C6H12O6) + Oxygen (6O2)
Carbon Dioxide
Carbon dioxide is involved in the fixation of carbon atoms to form organic molecules
As carbon dioxide concentration increases reaction rate will increase, as more organic molecules are being produced
At a certain concentration of CO2 photosynthetic rate will plateau, as the enzymes responsible for carbon fixation are saturated
Temperature
Photosynthesis is controlled by enzymes, which are sensitive to temperature fluctuations
As temperature increases reaction rate will increase, as reactants have greater kinetic energy and more collisions result
Above a certain temperature the rate of photosynthesis will decrease as essential enzymes begin to denature
Light Intensity
Light is absorbed by chlorophyll, which convert the radiant energy into chemical energy (ATP)
As light intensity increases reaction rate will increase, as more chlorophyll are being photo-activated
At a certain light intensity photosynthetic rate will plateau, as all available chlorophyll are saturated with light
Different wavelengths of light will have different effects on the rate of photosynthesis (e.g. green light is reflected)
Systems
What are the different human body systems?
Nervous
Respiratory
Circulatory
Digestive
Skeletal
Muscular
Systems can be static or dynamic, simple or complex.
Systems are sets of interacting or interdependent components.
Systems provide structure and order in human, natural and built environments.
Feedback Loops/ Systems
What are feedback loops?
System of responses that cause other reactions to respond.
Negative feedback loops
The reaction to the system to stimulus is to do the opposite
e.g the body reacts to fevers and if its too hot, system will cool down
Positive feedback loops
Increases the magnitude of change away from ideal set point
e.g contraction of the uterus from increasing oxytocin levels until the baby is born
Feedback systems
Our physiological feedback systems have three key features: a receptor, an intergrating center, and an effector
Communication in feedback systems
Endocrine Gland
A gland in the body which secretes hormones into the bloodstream.
Hormone
A chemical secreted by endocrine glands which carries instructions to the body.
Receptor
A specific site on a cell designed to recognize and accept a specific hormone.
How to maintain homeostasis?
Output– information sent from the control center travels down the (efferent) pathway to the effector.
Response– a response from the effector balances out the original stimulus to maintain homeostasis.
Human Body
In single-celled organisms, the cell must do all of the life functions (MRS GREN -> movement, respiration, sensitivity, growth, reproduction, excretion, nutrition).
Multicellular organisms have different levels of organisation
Cells
The basic unit
Plant cell vs Animal cell
Eukaryote vs Prokaryote
May have a specific function and structure (specialized cell)
Organisms
Entire living thing that can carry out all basic life processes.
Tissues
Made up of cells that are similar in structure and function, the cells work together to perform a specific activity.
Organs
Organs are made up of tissues that work together to perform a specific activity.
Organ Systems
Groups of two or more organs that work together to perform a specific function.