Cell Biology Flashcards

Vocabulary flashcards for cell biology exam review.

Cell

The basic structural and functional unit of all living organisms.

Robert Hooke

17th-century scientist who first used the word 'cell' to describe the small pores in a cork.

Anton van Leeuwenhoek

Dutch microbiologist who was the first scientist to describe cells and bacteria through observation under a microscope.

Cell Theory

All living things consist of cells, and all cells arise from pre-existing cells.

Cell Wall

A rigid, non-living layer found outside the cell membrane in plants, bacteria, and fungi.

Cellulose

The material that comprises the cell wall in plants.

Plasmodesmata

Openings in the cell wall that contain strands of cytoplasm connecting adjacent cells.

Cell Membrane (Plasma Membrane)

A membrane composed of carbohydrates, proteins, and a phospholipid bilayer that surrounds all plant and animal cells.

Selectively Permeable

The cell membrane's ability to allow certain substances in and out of the cell.

Nucleus

The largest organelle in the cell, containing all the cell's genetic information in the form of DNA.

Nuclear Membrane

Double-layered membrane made of lipids that separates the nucleus from the cytoplasm.

Nuclear Pores

Tiny holes in the nuclear membrane that regulate the exchange of materials between the nucleus and the cytoplasm.

Chromatin

Thin, long strands of DNA and protein found in the nucleus.

Nucleolus

Structure inside the nucleus that produces and assembles ribosomes.

Cytoplasm

Jelly-like fluid that fills the inside of the cell, composed of water, salts, and various organic molecules.

Turgor Pressure

Pressure exerted by the cytoplasm against the cell's membrane, helping to maintain the cell's shape.

Mitochondria

Organelles with double membranes responsible for producing ATP energy through aerobic respiration.

Cristae

Folds of the inner membrane of the mitochondria that increase surface area.

Ribosomes

Organelles composed of RNA and protein, responsible for protein synthesis.

Endoplasmic Reticulum (ER)

A network of hollow tubes, flattened sheets, and round sacs with a double membrane.

Smooth ER

Endoplasmic reticulum involved in the synthesis of lipids, metabolism of carbohydrates, regulation of calcium concentration, and detoxification of drugs.

Rough ER

Endoplasmic reticulum covered with ribosomes, responsible for protein synthesis and membrane production.

Golgi Body

Organelle that processes and packages proteins and lipids into vesicles for transport.

Plastids

Organelles found only in plants; include leucoplasts, chromoplasts and chloroplasts.

Leucoplasts

White plastids found in roots that store starch.

Chromoplasts

Plastids that contain red, orange, or yellow pigments.

Chloroplasts

Green-colored plastids found in plants and algae that convert the sun’s energy into oxygen and glucose through photosynthesis.

Stroma

Gel-like substance within the double membrane of the chloroplast, containing enzymes for photosynthesis.

Vacuoles

Membrane-bound, fluid-filled organelles that store water, nutrients, pigments, and waste products in plant cells.

Tonoplast

Selectively permeable membrane that surrounds the vacuole.

Lysosomes

Organelles surrounded by membranes that contain enzymes to digest food, destroy foreign substances, and break down worn-out organelles.

Vesicles

Small, membrane-bound spherical sacs that facilitate the metabolism, transport, and storage of molecules.

Centrioles

Organize microtubules that form the cell's skeletal system. (Found in animal cells only).

Fluid Mosaic Model

Describes the structure of the cell membrane, made of phospholipids and proteins.

Hydrophilic

Attracts water (referring to the head of a phospholipid).

Hydrophobic

Repels water (referring to the tail of a phospholipid).

Diffusion

The movement of molecules from areas of high concentration to areas of low concentration.

Osmosis

The movement of water molecules from a high water potential to a low water potential across a semi-permeable membrane.

Facilitated Diffusion

A special form of diffusion which allows rapid exchange of specific substances with the help of carrier proteins.

Active Transport

The process by which dissolved molecules move across a cell membrane from a lower to a higher concentration, requiring energy.