Preliminary Biology HSC - Cells as the Basis for life

structure

The arrangement of parts in an organism

function

the special, normal, or proper activity of an organ or part

cell membrane

the semipermeable membrane surrounding the cytoplasm of a cell.

organelles

Structures specialized to perform distinct processes within a cell.

prokaryotic cells

cells without a nucleus or other membrane-bound organelles

eukaryotic cells

Contain a nucleus and other organelles that are bound by membranes.

binary fission

A form of asexual reproduction in single-celled organisms by which one cell divides into two cells of the same size

genetic material

the set of instructions within a cell that controls an organism's characteristics and life processes

cytology

study of structure and function of cells

unicellular

A single celled organism

multicellular

Made up of more than one cell.

biochemistry

chemistry dealing with chemical compounds and processes in living plants and animals

cell differentiation

the process by which a cell becomes specialized for a specific structure or function.

photosynthesis

process by which plants and some other organisms use light energy to convert water and carbon dioxide into oxygen and high-energy carbohydrates such as sugars and starches

aerobic respiration

Respiration that requires oxygen

enzyme

a substance produced by a living organism that acts as a catalyst to bring about a specific biochemical reaction.

cytoskeleton

A network of fibers that holds the cell together, helps the cell to keep its shape, and aids in movement

fluid mosaic model

model that describes the arrangement and movement of the molecules that make up a cell membrane

lipids

Energy-rich organic compounds, such as fats, oils, and waxes, that are made of carbon, hydrogen, and oxygen.

carbohydrates

the starches and sugars present in foods

organic compound

a covalently bonded compound that contains carbon, excluding carbonates and oxides

inorganic compound

A compound that does not contain the element carbon or contains carbon bound to elements other than hydrogen.

endocytosis

process by which a cell takes material into the cell by infolding of the cell membrane

exocytosis

release of substances out a cell by the fusion of a vesicle with the membrane.

diffusion

Movement of molecules from an area of higher concentration to an area of lower concentration.

osmosis

Diffusion of water through a selectively permeable membrane

solute

A substance that is dissolved in a solution.

solvent

the substance in which the solute dissolves

solution

A homogeneous mixture of two or more substances

intracellular

within the cell

extracellular

outside the cell

concentration gradient

difference in the concentration of a substance from one location to another

ATP

(adenosine triphosphate) main energy source that cells use for most of their work

protein channel

Selective proteins in the cell membrane which open under certain conditions, therefore allowing only certain particles through

autotrophs

Organisms that are able to make their own food

heterotrophs

An organism that obtains organic food molecules by eating other organisms or their by-products.

chloroplast

organelle found in cells of plants and some other organisms that captures the energy from sunlight and converts it into chemical energy

chlorophyll

Green pigment in plants that absorbs light energy used to carry out photosynthesis

metabolic wastes

The wastes produced as a result of metabolism, including carbon dioxide, water, nitrogenous wastes and salts.

osmoregulation

regulation of solute concentrations and water balance by a cell or organism

vitamins

compounds that help regulate many vital body processes, including the digestion, absorption, and metabolism of other nutrients

enzyme

A type of protein that speeds up a chemical reaction in a living thing

enzyme substrate complex

A temporary complex formed when an enzyme binds to its substrate molecule(s).

denature

A change in the shape of a protein (such as an enzyme) that can be caused by changes in temperature or pH (among other things).

substrates

the reactants of enzyme-catalyzed reactions

pH

hydrogen ion concentration