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CELLS, BIOLOGICAL MOLECULES, MOVEMENT OF SUBSTANCES - Coggle Diagram
CELLS
organelles
vacuole.
in animal cell, there are numerous small and temporary vacuoles that store water and food substances rhat are partially permeable
in plant cell, it contains cell sap which contains dissolved substances such as mienral salts and sugars amino acids. It is partially permeable as well as large and central
ribosomes
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riibosomes attached to the rough endoplasmic recticulum synthesise proteins for secretion out of the cell
rough endoplasmic reticulum. helps to transport and package the proteins synthesised by the ribosomes to the golgi body for secretion out of the cell
smooth endoplasmic recticulum helps to turn harmful substances into harmless substances through detoxification and synthesise fats and hormones, such as steroids in mammals
mitochondria/ion. It helps to release energy from food for use through aerobic respiration, it is long and sausage-shaped and energy released is used to carry out cell activities such as reproduction
golgi body, It helps to further modify substances made by the endoplasmic recticulum and stores and packages the modified substances into vesicles for secretion out of the cell. vesicles are small membrane bound sacs that are formed by pinching off from membranes of certain organelles in the cell such as rough endoplasmic recticulum and golgi body
the proteins synthesised by the ribosomes attached to the rough endoplasmic recticulum is packaged into vesicles and pinched off the membrane of the rough endoplasmic recticulum. It is transported to the golgi body and fuses with the membrane, allowign the substances to be released inside it. The golgi body furhter modifies the substances and then stores and packages it as secretory vesicles and are pinched off the membrane and transported to the cell membrane, where they fuse with the cell membrane for secretion out of the cell and release their contents out of the cell
chloroplasts. they are only found in plant cells and help to photosynthesise and make food for the plant
cells are teh basic unit of life, it consists of living material called protoplasm, which is made up of cell membrane, nucleus and cytoplasm
cell membrane is a partially permeable membrane that allows certain substancer to enter, It controls the movement of substances in and out of the cell. it is made up of lipids and proteins, and is a thin and delicate sturcture.
cell wall is a fully permeable, inelastic protective layer that gives plants cells its shape. It is made of cellulose and is rigid.
cytoplasm. It is a jelly-like structure that fills the cell. It is a site where most reactions take place in the cell. It contains organelles, which are cellular structures that perform specific functions within a cell
nucleus. it controls the cells activities such as growht and repair of worn out cells and contains gentic informaiton stored in the form of chromosomes, which are long thread like structures that are made up of proteins and DNA. DNA contains hereditary information which provides instructions to the cell to carry out its activities such as growth and reproduction. When a cell is dividing, chromosmes condense and shorten to become a thick, rod shaped structure
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BIOLOGICAL MOLECULES
carbohydrates, basic unit is simple sugars, made up of hydrogen, carbon and oxygen, the proportion of hydrogen to oxygen is 2:1
single sugars : fructose, glucose
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complex carbohydrates: starch, cellulose and glycogen
glycogen can be foundin storage organs such as the liver and in muscles of mammals and in plants like potato tubers
glycogen and starch are ideal for storage in cells as they are both insoluble in water which prevents it from affecting the water potential in the cell and can be broken down easily into glucose when needed. It cannto pass through the partiallly permeable cell membrane which prevents it from getting lost and it is highly compressible, allowing it to occupy less space compared to individual glucose molecules
enzyme amylase hydrolyses the starch molecules into malrose molecules and the enzyme maltase hydrolyses the maltose molecules into glucose molecules
reducing sugars can be tested for using hte Benedicts solution. Place 2cm cube of food sample into a test tube. Place 2 cm cube of the Benedicts solution into the test tube and shake it vigourously. Heat the solution in a boiling water bath for 3-5 minutes and observe the colour change. If the solution changes from a blue to a brick red precipitate is formed, reducing sugars is present. If the solution remains blue, no reducign sugars are present. If the solution is green, traces fo reducign sugars are present and if the solution is yellow orange, moderate amount of reducign sugars are preseent
add a few drops of iodine onto the food sample. If the colour changes from brown to blue black, starch is present. If the colour remains brown, starch is not present
fats are a type of lipid, basic unit is glycerol and three fatty acids molecules
consists of carbon, hydrogen and oxygen but there are lesser oxygen molecules in proportion to hydrgogen molecules
eg. cheese, avocado and nuts are rich in fats
functions: a long term energy source and is a solvent for fat soluble vitamins and hormones. It acts as a protective layer that protects certain organs and is a natural insulating material that prevents excessive heat loss. It prevents water loss on our skin as oil substances secreated by the glands in the skin help to reduce water lloss and it is an essential part of cells in the cell membrane
the ethanl emulsion test can be used to test for the presence fo fats. Add 2 cm cube of sample intol a test tube and add an equal value of ethanol into the test tube. Shake the solution vigorously and if a white emulsion is formed, fats are persetn.
proteins are made up of hydrogen, carbon, oxygen, sulfur, phosphorus and nitrogen
the basic units are amino acids and proteins are the largest and most complex particles. E.g. meat, seafood, soy products
functions of proteins, they help to synthesise antibodies to combat diseases, synthesis new ccytoplasm for growth and repair of worn out cells and synthesise hormones and enzymes
the biuret test helps to test for the presence of proteins by placing 2 cm cube of th esolution and 2 cm cube of the food sample into a test tube. If proteins are present, the solution will turn from blue to violet. If not, the solution will remain blue.
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functions: a substrate for respiration to occur and provide energy for cell activities, excess fats can be converted into other organic compounds suhc as amino acids and fats, forms essential cell structures such as the cell membrane, forms nucleic acid such as DNA, synthesises lubricants such as mucus which consists of proteins and produces nectar in flowers
MOVEMENT OF SUBSTANCES
diffusion
the net movement of partticles from a region of higher concentration to a region of lower concentration, down a concentration gradient
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osmosis
the net movement of water molecules from a region of higher water potential to a region of lower water potential through a partially permeable membrane, down a water potential gradient
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active transport
requires energy from respiration and is the net movement of particles from a region of lower concentration to a region of higher concentration against the concentration gradient
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