Quick Revision Guide Flashcards

Flashcards for quick revision of cell structure, movement of substances, biological molecules, enzymes, nutrition, transport, respiration, excretion, and homeostasis in humans.

Cell

A unit of life consisting of a mass of living matter called protoplasm.

Partially Permeable Membrane

A membrane that allows only some substances to pass through it.

Concentration Gradient

Difference in concentration between two regions.

Diffusion

The net movement of particles from a region of higher concentration to a region of lower concentration.

Water Potential

Measure of the tendency of water to move from one place to another.

Osmosis

The net movement of water molecules from a region of higher water potential to a region of lower water potential, through a partially permeable membrane.

Active Transport

The process in which energy is used to move particles across a membrane against its concentration gradient.

Carbohydrates

Organic molecules made up of carbon, hydrogen, and oxygen, classified as single, double, or complex sugars.

Fats

Organic molecules made up of carbon, hydrogen, and oxygen, containing less oxygen in proportion to hydrogen than carbohydrates.

Proteins

Organic molecules made up of carbon, hydrogen, oxygen, and nitrogen (and sometimes sulfur); amino acids are their building blocks.

Catalyst

A substance that speeds up a chemical reaction without being chemically changed itself.

Enzymes

Proteins that function as biological catalysts, speeding up chemical reactions.

Activation Energy

The energy needed to start a chemical reaction.

Substrates

Substances on which enzymes act.

Denaturation

Change in the three-dimensional structure of an enzyme or soluble protein, caused by heat or chemicals.

Nutrition

The process by which organisms obtain food and energy for growth, repair, and maintenance.

Ingestion/Feeding

Taking in of food into the body.

Digestion

Process where large food molecules are broken down into smaller, soluble molecules.

Absorption

Process where digested food substances are absorbed into the bloodstream.

Assimilation

Process where absorbed nutrients are converted into new cytoplasm or used to provide energy.

Egestion

Process where undigested matter is removed from the body.

Peristalsis

Rhythmic, wave-like muscular contractions in the wall of the alimentary canal.

Circulatory System

The main transport system in humans, consisting of the heart, blood, and blood vessels.

Arteries

Blood vessels that carry blood away from the heart.

Veins

Blood vessels that carry blood back to the heart.

Cardiac Cycle

Sequence of events that takes place in one heartbeat.

Blood Pressure

Force that blood exerts on the walls of blood vessels.

Aerobic Respiration

Release of energy by the breakdown of glucose in the presence of oxygen.

Anaerobic Respiration

Release of energy by the breakdown of glucose in the absence of oxygen.

Oxygen Debt

Amount of oxygen required to remove lactic acid after anaerobic respiration.

Gas Exchange

The exchange of gases between an organism and the environment.

Excretion

Removal of metabolic waste products, toxic substances, and substances in excess of the body's requirements.

Deamination

Removal of the nitrogen-containing part of amino acids to form urea.

Nephrons

Basic functional units of the kidney where urine is formed.

Ultrafiltration

Process by which small molecules are filtered out of the blood by the glomerulus into the Bowman's capsule.

Selective Reabsorption

Process by which useful substances in the filtrate are reabsorbed back into the blood capillaries.

Osmoregulation

Control of water and solute concentrations in the blood to maintain a constant water potential.

Homeostasis

Maintenance of a constant internal environment.

Hormone

A chemical substance produced by an endocrine gland and transported in the bloodstream to target organs.