OCR GCSE Biology A Unit 1: Cell Level Systems

Light Microscope

Used to view whole cells or large subcellular structures of the cell.

Electron Microscope

Used to view subcellular structures more clearly and in more depth.

Nucleus

Controls the cell and contains genetic material.

Cytoplasm

Site where most chemical reactions occur.

Cell membrane

Barrier controlling the movement of substances into and out of the cell.

Mitochondria

Contains enzymes responsible for carrying out cellular respiration.

Cell wall

Made up of cellulose and gives the cell structural support (found in plant cells).

Vacuole

Contains cell sap and provides support (found in plant cells).

Chloroplasts

Site of photosynthesis and contains chlorophyll (found in plant cells).

Prokaryotes

Cells with nuclear material freely within the cytoplasm (e.g. bacteria).

Eukaryotes

Cells with a nucleus enclosed by a nuclear membrane (e.g. human cheek cell, amoeba, plant cells).

DNA

Polymer made up of two strands forming a double helix.

Protein Synthesis

Process of creating proteins from amino acids.

Enzymes

Biological catalysts that speed up chemical reactions inside organisms.

Active site

Site at which substrates fit into the enzyme.

Factors Affecting Enzyme Controlled Reactions

Temperature, pH, substrate concentration, and enzyme concentration.

Cellular Respiration

Process occurring inside plant and animal cells to release energy.

Aerobic Respiration

Respiration that occurs in the presence of oxygen.

Anaerobic Respiration

Respiration that occurs without the presence of oxygen.

Breakdown of Biological Molecules

Process of breaking down large molecules into smaller molecules using enzymes.

Carbohydrase

Enzyme that breaks down carbohydrates into glucose.

Protease

Enzyme that breaks down proteins into amino acids.

Lipase

Enzyme that breaks down lipids (fats) into fatty acids and glycerol.

Synthesis of Biological Molecules

Process of using smaller molecules to synthesize larger molecules needed by cells.

Photosynthesis

Process used by plants to make their own food using light energy, carbon dioxide, and water.

Endothermic

Reaction that absorbs heat energy from the surroundings.

Investigating Photosynthesis

Experiment to study the factors affecting the rate of photosynthesis.

Factors Affecting Photosynthesis

Temperature, carbon dioxide concentration, and light intensity.