Biology Lecture: Digestion, Circulation, and Cellular Processes

Comprehensive flashcards covering digestive enzymes, heart anatomy, microscopy, cell structures, stem cells, osmosis, and food chemical tests.

Peristalsis

Wave-like muscle contractions that move food through the digestive system.

Absorption

The movement of digested nutrients and water into the blood.

Emulsification

The process of breaking fat into smaller droplets to increase the surface area for lipase.

Stomach acid

Hydrochloric acid used to aid digestion.

Pulmonary artery

The blood vessel that carries deoxygenated blood from the heart to the lungs.

Valves

Structures found in veins that prevent the backflow of blood, which is not present in arteries.

Bile

A substance produced by the liver and stored in the gall bladder that neutralises stomach acid and emulsifies fats; it is not an enzyme.

Villi

Small projections in the small intestine that increase surface area for absorption.

Amylase

An enzyme produced in the salivary glands, pancreas, and small intestine that breaks down starch into sugars (maltose).

Protease

An enzyme that breaks down proteins into amino acids.

Lipase

An enzyme that breaks down lipids (fats) into fatty acids and glycerol.

Digestion

The process of breaking large insoluble food molecules into small soluble molecules.

Assimilation

The use of absorbed nutrients by cells.

Artery

A blood vessel with thick muscular/elastic walls and a narrow lumen that carries blood away from the heart at high pressure.

Vein

A blood vessel with thin walls and a wide lumen that carries blood towards the heart at low pressure.

Capillaries

Very thin blood vessels (one cell thick) that serve as the site of exchange of substances.

Magnification Formula

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Osmosis

The net movement of water particles from an area of high water concentration to an area of lower water concentration across a partially permeable membrane.

Nucleus

The part of an animal cell that controls cell activities.

Mitochondria

The site of aerobic respiration in a cell.

Ribosomes

The site of protein synthesis in a cell.

Independent Variable (Enzyme Practical)

The pH of the amylase solution or reaction mixture.

Enzymes

Biological catalysts.

Adult Stem Cells

Cells that can form a limited range of cell types and have fewer ethical concerns compared to embryonic stem cells.

Embryonic Stem Cells

Cells that can become any type of cell but involve ethical concerns because embryos are destroyed.

Iodine solution

A reagent used to test for starch; it turns from orange-brown to blue-black if starch is present.

Benedict's solution

A reagent used with heat to test for glucose (reducing sugar); it turns from blue to brick red for a positive result.

Biuret solution

A reagent used to test for protein; it turns from blue to purple/lilac for a positive result.

Ethanol test

A method to test for lipids; when mixed with ethanol and water, it turns from clear to cloudy white for a positive result.

Turgid

The state of a plant cell when it gains water by osmosis after being placed in pure water.

Plasmolysed

The state of a plant cell when it loses water by osmosis after being placed in a very salty solution.