Biology: Cell Structure and Microscopy (GCSE)

Vocabulary flashcards covering key concepts from Pages 1–3 notes: cell structure, organelles, prokaryotes vs eukaryotes, microscopy, genes, diffusion, and differentiation.

Animal cell

A eukaryotic cell that contains a nucleus and organelles; typical size about 10–30 micro m.

Nucleus

Encloses genetic material (DNA)

Mitochondria

Powerhouse of the cell; produces energy through aerobic respiration.

Cytoplasm

A gel-like substance where most chemical reactions occur.

Cell membrane

A bilayer that controls which molecules enter and leave the cell.

Ribosomes

Small particles where protein synthesis takes place.

Electron microscope

Microscope that uses electrons; allows us to see very small structures (e.g., ribosomes) with high resolution; more expensive and harder to use.

Plant cell

A cell with chloroplasts, cell wall and a large permanent vacuole. About 10–100 micro m.

Chloroplasts

Organelles containing chlorophyll; sites of photosynthesis in plant cells.

Permanent vacuole

Large vacuole filled with cell sap that helps maintain turgor and cell shape.

Cell wall

Rigid layer made of cellulose that strengthens plant cells.

Eukaryotes

Organisms whose cells have a nucleus; includes animals and plants.

Prokaryotic cells

Cells without a nucleus; genetic material not enclosed; generally smaller; bacteria are an example; DNA is a single loop.

Bacteria

An example of prokaryotic cells; unicellular organisms lacking a nucleus.

Light microscope

A microscope that uses light; relatively cheap and easy to use; lower resolution (about 200 nm); can view onion cells.

Electron microscope (EM)

Microscope that uses electrons; higher resolution (about 0.1 nm); more expensive and harder to use; can reveal mitochondria and other organelles.

Maximum resolution (light microscope)

Approximately 200 nanometres; limits the detail that can be resolved with light microscopy.

Maximum resolution (electron microscope)

Approximately 0.1 nanometre; enables viewing subcellular details like mitochondria.

Gene

The smallest unit of heredity 1st

Chromosome

A long DNA molecule that contains many genes and is packaged within the nucleus. 2nd

Nucleus (definition key point)

Organelle that houses genetic material. 3rd

Sperm cell

Male gamete, has a flagellum to swim, carries half the genetic material, many mitochondria, contains enzymes to penetrate the egg.

Differentiation

The process by which a cell changes to become specialised.

Specialised cells

Cells with a specific role, shape, and organelle composition tailored to their function.

Diffusion

The spreading out of particles from high concentration to low concentration.

Villi

Tiny projections in the small intestine that greatly increase surface area to enhance diffusion.

Oxygen

A gas moved across membranes by diffusion; essential for cellular respiration.

Carbon dioxide

A gas moved across membranes by diffusion; a waste product of respiration.

Photosynthesis

Process by which plants convert light into glucose in chloroplasts.

Aerobic respiration

Cellular respiration in mitochondria that requires oxygen to release energy.