Whole of Unit 2, AQA GCSE Biology - Organistation

Cell

Basic building block of living organisms

Tissue

Group of cells with similar structure and function.

Organ

Group of tissues working together to perform specific functions.

Organ System

Group of organs working together to a specific function.

Organism

Result of organ systems working together.

Enzyme

Protein molecule that speeds up body reactions.

Active Site

Region on an enzyme where substrate binds.

Lock and Key Model

Explanation of enzyme-substrate interaction.

Biological Catalyst

Enzyme that speeds up reactions in the body.

Metabolism

Reactions that build up and break down molecules.

Denature

Change in enzyme's shape, losing function.

pH

Measure of acidity or alkalinity.

Optimum pH

pH at which enzyme works at its highest rate.

Carbohydrase

Enzyme that breaks down carbohydrates.

Lipase

Enzyme that breaks down lipids.

Amylase

Enzyme that breaks down starch.

Protease

Enzyme that breaks down proteins.

Digestive System

Organs working together to digest and absorb food.

Carbohydrate

Important food group broken down by carbohydrase.

Starch

Complex carbohydrate broken down by amylase.

Glucose

Simple sugar produced from carbohydrate breakdown.

Insoluble Molecules

Large food molecules that cannot be absorbed into the bloodstream.

Salivary Amylase

Amylase produced in the mouth.

Pepsin

Enzymes produced in the stomach for protein digestion.

Pancreas and Small intestine

Organs that produce carbohydrase, lipase, amylase, and protease.

Proteins

Made of long chains of amino acids, broken down by protease enzymes

Amino Acids

Components of protein, broken down by protease enzymes

Lipids

Also known as fats, broken down by lipase enzymes into glycerol and fatty acids

Glycerol

Component of lipids broken down by lipase enzymes

Emulsification

Process of breaking large lipid droplets into smaller droplets by bile

Bile

Alkaline substance produced by the liver to emulsify fats in the small intestine

Iodine Test

Test for starch presence, changes color to blue-black with starch

Biuret Test

Test for protein presence, turns lilac in the presence of proteins

Ethanol Test

Test for lipid presence, forms a cloudy white emulsion with lipids

Benedict's Test

Test for sugar presence, changes color from blue to brick red with sugars

Artificial Pacemaker

An electrical device that sends regular impulses to regulate heartbeat if it’s irregular

Artery Structure

Thick muscle and elastic tissue, narrow lumen

Capillary Structure

Thin walls, one cell thick, short diffusion distance

Vein Structure

Thin walls, large lumen, often have valves

Plasma

Liquid part of blood, carries cells and substances

Red Blood Cell

carry oxygen from the lungs and deliver it throughout our body

White Blood Cell

Kills harmful microbes, part of the immune system

Platelets

Cell fragments that help blood clot

Coronary Arteries

Supply heart muscle with oxygenated blood

Coronary Heart Disease

Blockage in coronary arteries, reduces oxygen to heart

Statins

Drugs that slow down fatty buildup in arteries

Stent

Device to keep arteries open and improve blood flow

Faulty Heart Valves

Valves that don't open or close properly, affecting blood flow

Mechanical Heart Valve

Made of metal or plastic, long-lasting but risk of clotting

Biological Heart Valve

Usually from pig or cow, risk of rejection

Heart Failure

When the heart stops pumping effectively

Immunosuppressant Drugs

Weaken immune system to prevent rejection of foreign tissue

Donor Heart

Heart available for transplantation to replace a failing heart.

Artificial Hearts

Devices used to keep patients alive while waiting for a transplant.

Communicable Diseases

Illnesses that can be transmitted, caused by pathogens.

Non-Communicable Diseases

Health conditions not spread by pathogens, like heart disease.

White Blood Cells

Cells that protect against pathogens and infections.

Malignant Tumor

Cancerous growth invading neighboring tissues and spreading.

Benign Tumor

Non-cancerous abnormal cell growth contained in one area.

Risk Factors

Aspects of lifestyle or substances increasing disease likelihood.

Carcinogens

Chemicals that can cause cancer, often found in cigarette smoke.

Positive Correlation

Relationship where variables increase or decrease together.

Waxy Cuticle

Transparent layer on leaves reducing water loss through evaporation.

Palisade Mesophyll

Leaf tissue with chloroplasts for photosynthesis, located on top.

Spongy Mesophyll

Leaf layer with air spaces for gas exchange.

Stomata

Openings in leaves for gas exchange and water control.

Xylem Tissue

Plant tissue transporting water into the leaf.

Phloem Tissue

Tissue transporting sugars out of the leaf.

Translocation

Movement of dissolved sugars and molecules around a plant.

Transpiration Stream

Water movement from roots to leaves and evaporation through stomata.

Factors Affecting Transpiration

Temperature, air movement, light intensity, and humidity.

Oxygenated Blood

Blood rich in oxygen, ready to deliver to body tissues

Chambers of the Heart

Atrias and the ventricles

Valves

structures that prevent blood from flowing backward in the heart

Vena Cava

large vein that carries deoxygenated blood to the heart

Pulmonary Vein

Vein that carries oxygenated blood from the lungs to the heart

Pulmonary Artery

Artery that carries deoxygenated blood from the heart to the lungs

Aorta

Main artery that carries oxygenated blood from the heart to the body

Pacemakers

Group of cells that regulate the heartbeat by producing impulses