What are the parts of an animal cell/functions
Nucleus - Genetic material which controls the cell
Cytoplasm - Gel-like substance where most of the chemical reactions happen in the cell, it contains enzymes which control the reactions
Cell membrane - Holds the cell together and controls what enters and leaves
Mitochondria - Where the reactions for repiration happen
Ribosomes - Where proteins are made
What are the parts of a plant cell/ functions
Cell wall - Rigid wall made of cellulose which supports the cell and strengthens it
Permanant vaculoe - Contains cell sap which is a weak sollution of sugar and salts
Chloroplasts - Where photosynthesis occurs, they contain a green substance called chlorophyll
Yeast - Yeast is a single cell organism which has a cell membrane, nucleus, cytoplasm and a cell wall
Bacteria - cells have no nucleus, the bacteria cell has a cell membrane,cell wall and cytoplasm. The bacteria genetic information floats in the cell membrane
Diffusion and Diffusion in cells
DIFFUSION- THE GRADUAL MOVEMENT OF PARTICLES FROM A HIGH CONCENTRATION TO A LOW CONCENTRATION
- This happens in both liquids and gases
- The simplist form is in a gas e.g perfume in a room
- The bigger the difference in concentration the fast diffusion happens
- Dissolved substance move in and out of cells
- Small molecules like oxygen,glucose,amino acids and water can pass through the cell membrane
- starch and protein cant fit through
- particles move randomly
Palisade leaf cell - Allow photosynthesis
- It is packed with chloroplasts for photosynthesis. There's more in the top, closer to the light.
- Tall shape allows for alot of surface area to be exposed down the side,ready to absorb CO2 from the air.
- Thin shape means lots can be packed in the top of the leaf.
- They are grouped together at the top of the leaf.
Guard cells - Allow gas exchange and control water lose in the leaf
- Kidney shape which opens and closes the stomata in the leaf.
- When the plant has lots of water the guard cells fill up and go plump and turgid causing the stomata to open to exchange gases for photosyntheis.
- When the plant is short on the water the guard cells lose water and become flacid which closes the stomata, minimising the lose of water vapour.
- Thin outer walls and thick iner walls allow for opening and closing.
- Light sensitive and close at night to save water when photosynthesis isnt happeneing.
Red blood cells - Carry oxygen
- Concave shape gives a large surface area to carry the maximum about of oxygen and allows them to pass smoothly through capillaries.
- Packed with haemoglobin which is the pigment which absorbs the oxygen.
- No nucleaus to allow for more haemoglobin.
Sperm and Egg cells
Egg cell - carries female DNA and nourishs the developing embryo in the early stage, also contains huge food reserves to feed the embryo.
Sperm cell - Carries male DNA to the egg, it has a long tail and streamline head to help it swim to the egg. It contains alot of mitochondria to provide lots of energy. Sperm carries enzyme in its head to digest through the egg cell membrane.
Sperm fuses with the egg membrane and instantly changes it's structure to stop other sperm entering,this makes sure the offspring have the right amount of DNA.
- Large multicellular organisms have organ systems.
- Speciallised cells - tissues - organs - organ system
- Similar cells are organsism into tissues so they can work together to carry out a function
- Muscular tissue - Contracts to move
- Glandular tissue - Makes and secrets enzymes and hormones
- Epithelial tissue - Covers parts of the body e.g. inside of the gut
Tissues are organised into organs
Stomach is an organ made of
- Muscle tissue which moves the wall to turn up food
- Glandular tissue which makes digestive juices
- Epithelial tissues which lines the inside and outside of the stomach.
Organs are made into organ systems - E.G. Digestive system
The digstive system is made up of the stomach and small intestine (digest food) Liver (Produces bile) Small intestine (Absorbes soluble food molecules) Large intestine (Absorbes water from undigested food)