GCSE AQA biology – Topic 1: Cell Biology
Prokaryotic and Eukaryotic cells
There are 2 types of cells – eukaryotic and prokaryotic.
Eukaryotic cells: “complex cells”
These make up animals, plants, fungi, and protists.
Key points to know:
They are larger than prokaryotic cells (10–100 µm).
They have a nucleus that stores DNA as linear chromosomes.
They have specialised structures called organelles that are surrounded by
membranes.
They carry out all life processes within a single cell.
Organelles & Their Functions:
Nucleus – contains genetic material (DNA) that controls the activities of the
cell.
Cytoplasm – jelly-like substance where most chemical reactions take place.
Cell membrane – controls the movement of substances in and out of the cell.
Mitochondria – site of aerobic respiration → releases energy.
Ribosomes – where protein synthesis happens.
Plant cells have three extra structures:
Cell wall – made of cellulose, supports and strengthens the cell.
Chloroplasts – contain chlorophyll, where photosynthesis happens.
Permanent vacuole – filled with cell sap, keeps the cell turgid (firm).
REMEMBER NO OTHER CELLS HAVE THESE STRUCTURES.
Prokaryotic and Eukaryotic cells
There are 2 types of cells – eukaryotic and prokaryotic.
Eukaryotic cells: “complex cells”
These make up animals, plants, fungi, and protists.
Key points to know:
They are larger than prokaryotic cells (10–100 µm).
They have a nucleus that stores DNA as linear chromosomes.
They have specialised structures called organelles that are surrounded by
membranes.
They carry out all life processes within a single cell.
Organelles & Their Functions:
Nucleus – contains genetic material (DNA) that controls the activities of the
cell.
Cytoplasm – jelly-like substance where most chemical reactions take place.
Cell membrane – controls the movement of substances in and out of the cell.
Mitochondria – site of aerobic respiration → releases energy.
Ribosomes – where protein synthesis happens.
Plant cells have three extra structures:
Cell wall – made of cellulose, supports and strengthens the cell.
Chloroplasts – contain chlorophyll, where photosynthesis happens.
Permanent vacuole – filled with cell sap, keeps the cell turgid (firm).
REMEMBER NO OTHER CELLS HAVE THESE STRUCTURES.
