AQA A Level Biology - Cells and Transport

These flashcards cover key vocabulary and concepts from A Level Biology regarding cell structure and function, transport across cell membranes, and the immune system.

Eukaryotic Cells

Cells that contain membrane-bound organelles and a nucleus.

Prokaryotic Cells

Cells that lack membrane-bound organelles and a nucleus; DNA is free in the cytoplasm.

Cell-Surface Membrane

Selectively permeable membrane that controls passage of substances in and out of the cell.

Nucleus

Organelle that holds genetic information, site of DNA replication and transcription.

Ribosome

Site of protein synthesis made of ribosomal RNA and protein, not membrane-bound.

Rough Endoplasmic Reticulum (rER)

Studded with ribosomes, synthesizes, processes, and transports proteins.

Smooth Endoplasmic Reticulum (sER)

Synthesizes and processes lipids, such as cholesterol and steroid hormones.

Golgi Apparatus

Modifies proteins and lipids, packages them into vesicles for transport.

Mitochondria

Organelle where aerobic respiration occurs, producing ATP for energy release.

Chloroplasts

Organelles that absorb light for photosynthesis, producing organic substances.

Cell Wall

Rigid outer layer in plants, algae, and fungi providing mechanical strength, composed of cellulose or chitin.

Vacuole

Organelle that maintains turgor pressure in plant cells and stores substances.

Cell Cycle

Stages (Interphase, Mitosis, Cytokinesis) through which a cell goes to divide and produce identical daughter cells.

Binary Fission

A method of asexual reproduction in prokaryotes where the cell divides into two daughter cells.

Antigen

Foreign molecule that stimulates an immune response by stimulating antibody production.

Phagocytosis

Process where a phagocyte engulfs a pathogen and digests it using hydrolytic enzymes.

Mitosis

Process of nuclear division that results in two genetically identical nuclei.

Active Transport

Movement of molecules against a concentration gradient, requiring energy from ATP.

Facilitated Diffusion

Passive movement of molecules across a membrane via specific channel or carrier proteins.

Osmosis

Diffusion of water across a selectively permeable membrane from high to low water potential.

Monoclonal Antibody

Antibody produced from a single clone of B lymphocytes that targets a specific antigen.

Vaccine

Injection of antigens from weakened pathogens to stimulate an immune response and memory cell production.