Biology
Movement – all living organisms move. Respiration – all living organisms respire. Sensitivity – all living organisms respond to
their surroundings. Growth – all living organisms grow. Reproduction – all living organisms reproduce. Excretion – all living
organisms excrete waste products. Nutrition – all living organisms require nutrients. Control – all living organisms can make
themselves move.
Plants are multicellular – they contain chloroplasts so can carry out photosynthesis. They have cellulose cell walls. They store
carbohydrates as starch or sucrose. Examples are daffodils and oak trees.
Animals are multicellular organisms which do not contain chloroplasts and do not photosynthesize. They have no cell walls.
They usually have nervous co-ordination and are able to move on their own accord. They store carbohydrates as glycogen.
Examples are dogs and monkeys.
Fungi cannot carry out photosynthesis. Their body is usually made into a mycelium made of thread-like structures called
hyphae which contain many nuclei. Some are single-celled, with chitin cell walls. They feed by extracellular secretion of
digestive enzymes onto food material and absorb the natural products (saprotrophic nutrition). They store carbohydrates as
glycogen. Examples include mucor and yeast.
Bacteria are microscopic single-celled organisms. They have a cell wall, cell membrane, cytoplasm and plasmids but a
circular chromosome of DNA instead of a nucleus. Some carry out photosynthesis but most feed off other living or dead
organisms. Examples include lactobacillus bulgaricus and pneumococcus.
Proctoctists are usually unicellular. Some are animal / fungus like (amoeba) and obtain food by outside sources. Some are
plant like (algae) and produce their own nutrients. Some are pathogens, like plasmodium which causes malaria.
Viruses are small parasitic particles that can only reproduce inside living organisms. They vary in shape and size but have no
cellular structure – they have a protein coat and contain either DNA or RNA. Examples include tobacco mosaic virus and the
HIV virus which causes AIDS. Viruses can infect all living organisms.
A pathogen is a microorganism which causes disease. They may be fungi, bacteria, protoctists or viruses.
The order of organization in an organism is organelles, cells, tissues, organs, organ systems.
The nucleus contains genetic material which controls the activity of the cell.
The cytoplasm is where chemical reactions take place, controlled by
enzymes. The cell membrane controls the movement of substances into and
out of the cell. The mitochondria is where most energy is released by
respiration. The ribosomes are where protein synthesis happens.
The cell wall strengthens the cell. The chloroplasts contain chlorophyll which
absorbs light for photosynthesis. The permanent vacuole is filled with sap to
keep the cell turgid.
Animal cells don’t have cell walls, chloroplasts or vacuoles.
Carbohydrates and lipids (fats and oils) are made of carbon, hydrogen and
oxygen. Proteins contain carbon, hydrogen, oxygen, nitrogen, phosphorus and sulfur.
Carbohydrates, proteins and lipids are large molecules made up of smaller base units. Starch and glycogen are made of
simple sugars. Protein is made from amino acids. Lipids are made of fatty acids and glycerol.
To test for glucose, warm the object with benedict’s solution. If it turns from blue to orange then glucose is present.
To test for starch, add iodine to the object and if it turns from yellow/brown to blue/black, starch is present.
Enzymes lower the activation energy of a reaction to make it faster. They are unchanged from the beginning to the end of the
reaction. They are catalysts.
Enzymes have an optimum temperature (around 40oC) when they act fastest. High temperatures denature them as the shape
of the active site is changed so it can’t bind with the substrate. Low temperatures slow down the reactions.
Enzymes also have an optimum pH – If the pH is too different from the optimum then the bonds that hold the enzyme
together could be broken, denaturing them. An extreme pH will generally denature any enzyme.
To test the rate of enzyme reaction with temperature, add starch to a test tube. Add amylase and drop the mix onto white
tiles. Time how long it takes for the iodine to stop being blue/black. Repeat at different temperatures.
Diffusion is the intermingling of substances facilitated by the natural movement of their particles. Osmosis is the net
movement of water molecules over a partially permeable membrane from an area with more water molecules to an area with
fewer. Active transport is the movement of molecules across a cell membrane into a region of higher concentration requiring
energy. All of these can move substances into and out of cells.
Turgid cells are important to support the structure of a plant.
The factors that affect the rate of movement of substances into and out of a cell are surface area to volume ratio, temperature
and concentration gradient.
An experiment for osmosis in non-living systems is putting food coloring in water. You time how long it takes for the liquid to
all become the same color. You then change the temperature and repeat the experiment. The higher the heat, the faster the
osmosis. To experiment on osmosis in living systems, cut two pieces of potato and weigh them. Put one in distilled water and
Movement – all living organisms move. Respiration – all living organisms respire. Sensitivity – all living organisms respond to
their surroundings. Growth – all living organisms grow. Reproduction – all living organisms reproduce. Excretion – all living
organisms excrete waste products. Nutrition – all living organisms require nutrients. Control – all living organisms can make
themselves move.
Plants are multicellular – they contain chloroplasts so can carry out photosynthesis. They have cellulose cell walls. They store
carbohydrates as starch or sucrose. Examples are daffodils and oak trees.
Animals are multicellular organisms which do not contain chloroplasts and do not photosynthesize. They have no cell walls.
They usually have nervous co-ordination and are able to move on their own accord. They store carbohydrates as glycogen.
Examples are dogs and monkeys.
Fungi cannot carry out photosynthesis. Their body is usually made into a mycelium made of thread-like structures called
hyphae which contain many nuclei. Some are single-celled, with chitin cell walls. They feed by extracellular secretion of
digestive enzymes onto food material and absorb the natural products (saprotrophic nutrition). They store carbohydrates as
glycogen. Examples include mucor and yeast.
Bacteria are microscopic single-celled organisms. They have a cell wall, cell membrane, cytoplasm and plasmids but a
circular chromosome of DNA instead of a nucleus. Some carry out photosynthesis but most feed off other living or dead
organisms. Examples include lactobacillus bulgaricus and pneumococcus.
Proctoctists are usually unicellular. Some are animal / fungus like (amoeba) and obtain food by outside sources. Some are
plant like (algae) and produce their own nutrients. Some are pathogens, like plasmodium which causes malaria.
Viruses are small parasitic particles that can only reproduce inside living organisms. They vary in shape and size but have no
cellular structure – they have a protein coat and contain either DNA or RNA. Examples include tobacco mosaic virus and the
HIV virus which causes AIDS. Viruses can infect all living organisms.
A pathogen is a microorganism which causes disease. They may be fungi, bacteria, protoctists or viruses.
The order of organization in an organism is organelles, cells, tissues, organs, organ systems.
The nucleus contains genetic material which controls the activity of the cell.
The cytoplasm is where chemical reactions take place, controlled by
enzymes. The cell membrane controls the movement of substances into and
out of the cell. The mitochondria is where most energy is released by
respiration. The ribosomes are where protein synthesis happens.
The cell wall strengthens the cell. The chloroplasts contain chlorophyll which
absorbs light for photosynthesis. The permanent vacuole is filled with sap to
keep the cell turgid.
Animal cells don’t have cell walls, chloroplasts or vacuoles.
Carbohydrates and lipids (fats and oils) are made of carbon, hydrogen and
oxygen. Proteins contain carbon, hydrogen, oxygen, nitrogen, phosphorus and sulfur.
Carbohydrates, proteins and lipids are large molecules made up of smaller base units. Starch and glycogen are made of
simple sugars. Protein is made from amino acids. Lipids are made of fatty acids and glycerol.
To test for glucose, warm the object with benedict’s solution. If it turns from blue to orange then glucose is present.
To test for starch, add iodine to the object and if it turns from yellow/brown to blue/black, starch is present.
Enzymes lower the activation energy of a reaction to make it faster. They are unchanged from the beginning to the end of the
reaction. They are catalysts.
Enzymes have an optimum temperature (around 40oC) when they act fastest. High temperatures denature them as the shape
of the active site is changed so it can’t bind with the substrate. Low temperatures slow down the reactions.
Enzymes also have an optimum pH – If the pH is too different from the optimum then the bonds that hold the enzyme
together could be broken, denaturing them. An extreme pH will generally denature any enzyme.
To test the rate of enzyme reaction with temperature, add starch to a test tube. Add amylase and drop the mix onto white
tiles. Time how long it takes for the iodine to stop being blue/black. Repeat at different temperatures.
Diffusion is the intermingling of substances facilitated by the natural movement of their particles. Osmosis is the net
movement of water molecules over a partially permeable membrane from an area with more water molecules to an area with
fewer. Active transport is the movement of molecules across a cell membrane into a region of higher concentration requiring
energy. All of these can move substances into and out of cells.
Turgid cells are important to support the structure of a plant.
The factors that affect the rate of movement of substances into and out of a cell are surface area to volume ratio, temperature
and concentration gradient.
An experiment for osmosis in non-living systems is putting food coloring in water. You time how long it takes for the liquid to
all become the same color. You then change the temperature and repeat the experiment. The higher the heat, the faster the
osmosis. To experiment on osmosis in living systems, cut two pieces of potato and weigh them. Put one in distilled water and
