Biology - Cells structure and function Flashcards
A+P What is the nucleus and what does it do?
A+P The nucleus controls all the activities of the cell and is surrounded by the nuclear membrane. It contains the genes on the chromosomes that carry the instructions for making the proteins needed to build new cells or new organisms. The average diameter is around 10 micrometres.
A+P What is cytoplasm and what does it do?
A+P The cytoplasm is a liquid gel in which the organelles are suspended and where most of the chemical reactions needed for life take place.
A+P What is the cell membrane and what does it do?
A+P The cell membrane controls the passage of substances such as glucose and mineral ions into the cell. It also controls the movement of substances such as urea or hormones out of the cell.
A+P What are mitochondria and what do they do?
A+P Mitochondria are structures in the cytoplasm where aerobic respiration takes place, releasing energy for the cell. They are very small: 1-2 micrometres in length and only 0.2-0.7 micrometres in diameter.
A+P What are ribosomes and what do they do?
A + P Protein synthesis happens here which makes all the proteins needed in the cell.
P What are chloroplasts and what do they do/contain?
P Chloroplasts are found in all the green parts of a plant. They are green because they contain the green substance chlorophyll. Chlorophyll absorbs light so the plant can make food by photosynthesis. Each chloroplast is around 3-5 micrometres long. Root cells do not have chloroplasts because they are underground and do not photosynthesise.
What is the vacuole and what do they contain?
The vacuole is a space in the cytoplasm filled with cell sap. This is important for keeping the cells rigid to support the plant.
Do animal or plant cells have a cell wall?
Only plant and algal cells have a cell wall made of cellulose that strengthens the cell and gives it support.
