Biology - Cells
- Created by: Maddie A-P
- Created on: 04-04-15 12:40
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- Cells
- Animal cells
- Nucleus - contains genetic material that controls the activities of the cell.
- Cytoplasm - gel-like substance where most of the chemical reactions happen. Contains enzymes that control these chemical reactions.
- Cell Membrane - holds the cell together and controls what goes in and out.
- Mitochondria - not the powerhouse of the cell! xD They are where most of the reactions for respiration take place.
- Ribosomes - These are where proteins are made.
- Plant Cells
- Plant cells usually have the same bits as animal cells, plus a few extras.
- They have rigid cell wall made of cellulose which supports the cell and strengthens it.
- Permanent Vacuole - contains cell sap, a weak solution of sugar and salts.
- Chloroplasts - these are where photosynthesis occurs, which makes food for the plant. They contain a green substance called chlorophyll.
- Bacteria Cells
- Bacteria cells do not have a nucleus.
- They are single-celled microorganisms.
- A bacterial cell has cytoplasm and a cell membrane surrounded by a cell wall.
- The genetic material floats in the cytoplasm because bacterial cells don't have a nucleus.
- Yeast Cells
- Yeast is a single-celled organism.
- Yeast is a microorganism.
- A yeast cell has a nucleus, cytoplasm, and a cell membrane, surrounded by a cell wall.
- Specialised Cells
- Palisade leaf cells are adapted for photosynthesis
- They're packed with chloroplasts
- Their tall structure means they have a big surface area for absorbing CO2.
- Their thin structure means that you can fit lots of them in the top of a leaf.
- Guard Cells are adapted for gas exchange and controlling water loss
- Are a special Kidney shape which opens and closes the stomata in a leaf.
- When the plant has lots of water, the guard cells fill with it and go plump. This makes the stomata open so gasses can be exchanged for photosynthesis.
- Thin outer walls and thickened inner walls make the opening and closing work.
- They're sensitive to light and close at night to save water.
- Red Blood Cells are adapted to carry oxygen
- Their concaved shape gives a big surface area for absorbing oxygen.
- It also helps them to pass smoothly through capillaries to reach body cells.
- They're packed with haemoglobin - the pigment that absorbs the oxygen.
- They haven't got a nucleus to save more room for haemoglobin.
- Their concaved shape gives a big surface area for absorbing oxygen.
- Sperm and egg cells are specialised for reproduction.
- The main functions of an egg cell are to carry to female DNA and to nourish the developing embryo in the early stages.
- When a sperm fuses with the egg, the eggs membrane instantly changes its structure to stop any more sperm getting in.
- This makes sure the offspring ends up with the right amount of DNA.
- The function of a sperm cell is to get the male DNA to the female DNA.
- The sperm has a long tail and a streamlined head to help it swim to the egg. There are a lot of mitochondria in the cell to provide the energy needed.
- The sperm also carry enzymes in their heads to digest through the egg cell membrane.
- Palisade leaf cells are adapted for photosynthesis
- Animal cells
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