Success Criteria for Topic 1: Cell Structure
I will know I am successful in Topic 1 if I can state the following:
o Cells contain organelles which have functions.
o
o
o
o Bacterial cells are different from animal and plant cells as
they have no organelles which have membranes and their cell
wall is chemically different.
o Fungi have a cell wall which is not made of cellulose.
Success Criteria for Topic 1: Cell Structure
o Bacteria have plasmids and circular DNA.
o
o
o
Organelle
mitochondria
o
chloroplast
o
Cell
membrane
o
vacuole
o
nucleus
o
o
o
ribosome
plasmid
Cell wall
function
o
ATP is produced here when oxygen is
present
o
absorbs light energy for
photosynthesis
o
Controls movement of substances in
and out of cell
o
stores water and solutes to regulate
water content
o
controls cell activities and passes info
to next generation
o
where proteins are formed
o
small circle of DNA found in bacteria
o
Provides shape and support to cells
Success Criteria for Topic 2: Transport across the cell
membrane
I will know I am successful in Topic 2 if I can state the following:
o
o Cell membranes are made of lipids with protein molecules
scattered between.
o This structure is called the fluid mosaic model as the proteins
are scattered among the phospholipids and the proteins can
move.
o Some substances can move in and out of the cell membrane
while others cannot.
o Diffusion is the movement of substances down the
concentration gradient.
o Diffusion needs no energy.
Success Criteria for Topic 2: Transport across the cell
membrane
o Substances in high concentration outside the cell and needed
by the cell enter by diffusion.
o Cells need oxygen, glucose and amino acids and produce carbon
dioxide.
o Osmosis is the movement of water from high to low
concentration across a semi permeable membrane.
o Water enters a cell by osmosis down the water concentration
gradient.
o If water enters a plant cell by osmosis it becomes turgid.
o If water leaves a plant cell by osmosis it becomes plasmolysed.
o If water enters an animal cell by osmosis it may burst.
o If water leaves an animal cell by osmosis it will shrink
o When potato is placed in water, the water enters and the
potato gets bigger.
o If a potato is placed in a strong salt solution there is more
water in the potato cells so water leaves the potato and it
shrinks.
o Active transport is when a substance moves across a cell
membrane against a concentration gradient, carried by a
protein molecule. It needs energy.
Success Criteria for Topic 2: Transport across the cell
membrane
o Sodium and potassium move in and out of a nerve cell by active
transport.
o Both active transport, osmosis and diffusion involve substances
moving across the cell membrane.
o Active transport unlike diffusion is movement up the
concentration gradient and it needs energy.
o Active transport involves protein molecules which carry the
substances across and act as a ‘pump’.
Success Criteria for Topic 3: Producing new cells
I will know I am successful in Topic 7 if I can state the following:
o Body cells have 2 sets of chromosomes and are diploid.
o Cells which have only 1 set of chromosomes are haploid.
o Gametes such as sperm and egg are haploid.
o Cheek cells, white blood cells and bone cells are diploid.
o A zygote and embryo are diploid.
o A haploid sperm and a haploid egg fuse to form a diploid zygote
which goes on to divide by mitosis.
o Cell division by mitosis keeps the chromosome number
(complement) the same.
o Cell division by mitosis allows organisms to grow, replace and
repair.
o The nucleus contains chromosomes and controls the cell
activities.
o Cells require 2 sets of chromosomes so they can have a full set
of information for complete cell function.
Success Criteria for Topic 3: Producing new cells
o Stages of mitosiso The chromosomes (DNA strands) make copies of themselves.
o
o The 2 copies are called chromatids and they line up on the
equator of the cell.
o Spindle fibres pull the chromatids apart to opposite poles.
o The cytoplasm divides and the nuclear membrane reforms.
o 2 separate identical cells are formed.
o Cell culture allows the growing of cells in a dish in a lab.
o To produce cells by cell culture, aseptic techniques, the
correct medium, pH, temperature and oxygen levels are
needed.
o Aseptic techniques- lab coat to be worn, hands washed before
and after, work surfaces disinfected before and after, all
equipment and media sterilised, inoculating loops flamed
before and after, Petri dish lids only opened when needed and
then sealed and all used plates disposed of when finished in a
plastic bag to be autoclaved.
o Cells can be grown in agar or broth as mediums.
o A fermenters is a container used to grow cells. Oxygen, temperature and pH are
controlled, substrates enters and products are removed.
Success Criteria for Topic 4: DNA and the production of
proteins
I will know I am successful in Topic 7 if I can state the following:
o DNA is a found in the nucleus.
o It carries the code to produce proteins.
o It has 2 strands held together by 4 complementary base pairs
- A, T, C, G.
o A combines with T and C combines with G.
o DNA is a double helix held together by the complimentary base
pairs.
o The base order decides the order amino acids are joined
together and this decides which protein is produced.
o The order of the bases is called the genetic code and it is held
in the chromosomes.
o The protein is put together in the cytoplasm on a ribosome.
o DNA is too big a molecule to leave the nucleus so a smaller
molecule called mRNA copies the DNA code and takes it out
into the cytoplasm to a ribosome.
o mRNA is a single strand with the DNA code on it.
o The amino acids line up along the RNA acording to the order of
the bases on the RNA.
o Amino acids are held together by peptide bonds.
I will know I am successful in Topic 7 if I can state the following:
o Protein molecules have different shapes and amino acid orders,
this decides the protein function.
o All proteins are made of amino acids.
o Amino acids are held together by peptide bonds.
o There are over 20 different amino acids.
o Different amino acid orders give different proteins with
different functions.
o Enzymes have an active site which fits their substrate and are
denatured by high temperatures. It changes the shape of the
active site.
o Proteins also make hormones which are chemical messengers,
antibodies which fight infection, protein carriers which
transport substances across cell membranes and some form
hair and nails.
o Enzymes are biological catalysts which speed up chemical
reactions but are unchanged by them and are found in all living
things.
o Because enzymes are proteins they work best at optimum
temperature and ph.
o They only speed up reactions when at optimum conditions. At
low temperatures enzymes work slowly, at high temperatures
they change shape (denatured) and stop working.
Success Criteria for Topic 5: Proteins and enzymes
o Enzymes are all specific, have optimum conditions and all speed
up reactions
o Some enzymes break large molecules down (digest) into smaller
ones, some build up (synthesis) small molecules into large ones.
o Enzymes include amylase which breaks starch into maltose,
lipase which breaks fats down into fatty acids and glycerol,
catalase which breaks hydrogen peroxide into oxygen and
water and pepsin which breaks proteins down into peptides.
o Enzymes fit their substrate exactly like a lock and key.
o Because the shape of a substrate must be exactly
complementary to the enzyme at the active site it is specific.
o Above 45 degrees the active site changes shape and the
substrate will not fit.
o This is denaturing.
Denaturing
o
o Enzymes are most active at their optimum temperature and
less active either side of this temperature.
Success Criteria for Topic 5: Proteins and enzymes
o Enzymes work best at optimum conditions eg temp, pH.
o Enzymes lower the energy needed for a reaction to take place.
o Pepsin has a working pH range of 1.6-4.5, amylase 5.1-8.9, and
catalase 6- 11.9.
o Catalase works best at pH9, amylase 7, pepsin 2.5.
Success Criteria for Topic 6: Genetic Engineering
I will know I am successful in Topic 7 if I can state the following:
o DNA can be transferred naturally by bacterial plasmids or
viruses.
o DNA can also be transferred by genetic engineering.
o To begin genetic engineering the gene needed is identified,
removed and cut out of the chromosome using enzymes.
o The plasmid from the bacteria is removed and cut open with
the enzyme and the required gene inserted using another
enzyme.
o The plasmid is put into another bacterium which multiplies with
the new gene present in the next generation of bacteria.
o Examples of genetic engineering are blight resistant potatoes,
bacteria producing human insulin and growth hormone.
Success Criteria for Topic 7: Photosynthesis
I will know I am successful in Topic 7 if I can state the following:
o Word equation iscarbon dioxide + water -> glucose+sugar +oxygen, using light
energy and chlorophyll.
o Raw materials for photosynthesis are carbon dioxide and
water.
o By product of photosynthesis is oxygen.
o Light and chlorophyll are also requirements.
o Photosynthesis is a series of enzyme controlled reactions in 2
stages.
o Light energy is changed into chemical energy.
o The first stage is the Light reaction.
o Water is split into hydrogen and oxygen. Excess oxygen
diffuses from the cells and the hydrogen and ATP are used in
the next stage.
o The next stage is Carbon Fixation.
o Hydrogen joins with carbon dioxide.
o Hydrogen and carbon dioxide form glucose.
o ATP produced in photolysis provides the energy.
o Glucose can be used for respiration by the plant or converted
into starch for storage or cellulose for new cell walls.
Success Criteria for Topic 7: Photosynthesis Continued
o A limiting factors if present in limited amounts slows a
reaction down.
o Carbon dioxide, temperature and light can limit the rate of
photosynthesis and are known as limiting factors.
o
o At A1 light is the limiting factor but at A2 carbon dioxide is
the limiting factor.
Success Criteria for Topic 8: Respiration
I will know I am successful in Topic 8 if I can state the following:
o The chemical energy in glucose is released in a series of
enzyme controlled reactions called respiration.
o Respiration generates ATP from ADP and phosphate.
o Glucose + oxygen -> water +carbon dioxide + ATP is the word
equation for aerobic respiration.
o Products of aerobic respiration are water, carbon dioxide and
ATP.
o The breakdown of a glucose molecule without oxygen in animal
cells to lactic acid produces 2 ATP molecules (lactic acid
fermentation).
o Products of anaerobic respiration in animal cells are lactic acid
and a small amount of ATP.
o The breakdown of a glucose molecule without oxygen in plant
and yeast cells produces alcohol, carbon dioxide and 2ATP
molecules (alcohol fermentation).
o Products of anaerobic respiration in yeast cells are alcohol,
carbon dioxide and a small amount of ATP.
o Glucose contains chemical energy.
o Respiration releases the energy in living cells.
o During respiration molecules of ADP and phosphate join
together to make ATP.
Success Criteria for Topic 8: Respiration
o ATP is a high energy compound.
o ADP + phosphate -> ATP.
o ATP breaks down to produce ADP and a phosphate and releases
the energy stored.
o This energy can be used for muscle contraction, mitosis, cell
repair, protein formation and heat.
o Heat energy provides enzymes with the correct temperature
to work well.
o The breakdown of a glucose molecule with oxygen to produce
carbon dioxide and water produces 38 ATP molecules.
o Glucose-> pyruvate-> carbon dioxide+water+38 ATP.
o Glucose -> pyruvate takes place in the cytoplasm. The next
stage takes place in the mitochondria.
o The breakdown of a glucose molecule without oxygen in plant
and yeast cells produces alcohol, carbon dioxide and 2ATP
molecules (alcohol fermentation).
o Fermentation occurs in the cytoplasm.
o Anaerobic respiration (fermentation) takes place in the
cytoplasm of yeast cells.
o Anaerobic respiration in muscle cells produces only 2 ATP.
o During anaerobic respiration in muscle cells pyruvate acid
breaks down into lactic acid.