Plant and animal cells
Has all the bits that the animal cell has plus:
Permanent Vacuole- contains cell sap, weak solution of sugar and salts. Nucleus-contains genetic material and controls activities of cells Cytoplasm-gel like substance where all the chemical reactions take place Cell membrane- holds cell together and controls what goes IN and OUT Mitochondria- reactions for respiration takes place Ribosomes-proteins are made here
Lots of cells= tissues = organs = organ systems
Specialised cells-Palisade cells, Guard cells,Red blood cells and sperm and egg cell
-Palisade cells are packed with chloroplasts for photosynthesis. - Crammed at top of cell so are near light.
-Tall shape means lots of surface area for absorption of Carbon dioxide. -Thin shape means that you can pack lots of them at the top of the leaf.
Red Blood cells
Concave shape gives big surface area for aborption of oxygen and can pass through capillaries. Packed with haemoglobin- pigment that absorbs oxygen No nuclues- so have enough room for the haemoglobin, important part of blood, blood is a tissue. Sperm and egg cell
Main functions of an egg cell are to carry the female DNA and nourish the developing embryo in the early stages. * When sperm fuses with egg, the eggs membrane changes its structure to stop any sperm from getting in. This is so the offspring end up with the right amount of DNA. Function of sperm is to get the male DNA to the female DNA. Has long tail, and streamlined head to help it swim to egg. Mitonchondria are in the cell to provide energy needed. Sperms carry enzymes in head to digest through the egg cell membrane.
Guard cells- Open and close pores
Special kidney shape which opens and closes pores in a leaf. When plant has lots of water it goes plump and turgid. Makes stomata open so gases are exchanged for photosynthesis. When plant is short of water the guard cell becomes flaccid,making the stomato close. Thin outer walls and thicker inner walls.
Sensitive to light and close at night to save water without losing out on photosynthesis.
Diffusion- Passive movemnet of particles from an area of high concentration to an area if low concentration -happens in both liquids and gases-because particles are free to move around. - Only small molecules can diffuse e.g. glucose,amino acids, water and oxygen. big molecules like starch and proteins and starch cant fit through the membarne. Three things which the rate of diffusion depends on-
-Distance- substances diffuse more quickly when they havent got far to move. - Concentration difference-substances duffuse faster if theres a big difference in concentration. -Surface area- the more surface there is available for molecules to move across, the faster they can get from one side to another side.
* Balanced equation for photosynthesis:
It requires four main things:
-Light, carbon dioxide, water and chlrophyll.
The light comes for Sun
Carbon dioxide comes from air
Water comes for soil
Chlrophyll comes fro chloroplasts. It is a green pigment which absorbs energy in sunlight. Plants use the glucose
* For respiration, to manufacture glucose in their leavs
* Making fruits. Glucose with fructose and sucrose are for storing in fruits. Fruits taste nice so that animals will eat them and spread the seeds all over the place with their poo. * Making cell walls, glucose is converted into cellulose for making cell walls * Making proteins. Glucose is combined with the nitrates to make amino acids which then make proteins. * Stored in seeds, glucose is turned into lipids for storing in seeds. * Stored as starch, Glucose is turned into starch and stored in roots, stems, leaves,
Minerals for healthy growth
Nitrates- needed for amino acids which are used to make proteins. Magnesium needed to make chlorophyll, which is needed for...