Summarised Flash Cards

Flashcards about food, digestion, and respiration

Nutrition information labels

Tell us what the food contains and how much chemical energy is stored in the food, measured in kilojoules (kJ).

Healthy Diet

Contains the right balance of different foods needed and the right amount of energy.

Carbohydrates

Provide energy and make cell structures; good sources include pasta and bread.

Fats

Provide energy, insulation, and are used in cell structures.

Proteins

Control cell reactions (as enzymes) and build cell structures; good sources include meat and beans.

Vitamins and Minerals

Help our bodies function well; examples include vitamin C (in fruits and vegetables) and calcium (in dairy products).

Fibre

Helps to keep our intestines clean and prevent constipation; found in wholemeal bread.

Water

An important solvent in the body.

Malnourishment

Occurs when a diet is not balanced, potentially leading to being overweight, underweight, or developing diseases.

Deficiency Diseases

Result from a lack of essential nutrients in the diet.

Exercise

Increases the amount of energy expended by the body, leading to better health.

Metabolic Rate

The rate at which all the chemical reactions in the cells of the body are carried out.

Stomach Tissue Types

Muscular tissue (churning), glandular tissue (digestive juices), and epithelial tissue (covering).

Digestive System Components

Glands (pancreas, salivary glands), stomach, small intestine, liver, and large intestine.

Enzymes

Proteins that act as biological catalysts, controlling reactions inside and outside cells.

Catalysts

Increase the rate of chemical reactions.

Biuret Solution

Used to test for protein; a color change from light blue to lilac indicates the presence of protein.

Fat Test

Rub food on paper; translucent paper indicates the presence of fat.

Benedict’s Solution

Used to test for glucose; color change (green, yellow, orange, brick-red) after heating indicates the presence of glucose.

Iodine Solution

Used to test for starch; a color change from orange to blue-black indicates the presence of starch.

Optimum Temperature (Enzymes)

The temperature at which an enzyme works fastest; typically up to approximately 40°C.

Denatured Enzyme

An enzyme whose structure has changed due to high temperature, causing the active site to change shape.

Extracellular Enzymes

Enzymes that work outside the body cells.

Digestion

The process where food is broken down into substances the body can absorb.

Nutrition

The process of taking in and using food.

Amylase

An enzyme, found in saliva, that digests starch into maltose (smaller sugars).

Pepsin

A protease enzyme found in the stomach that digests proteins into amino acids.

Hydrochloric Acid (in Stomach)

Kills bacteria in food and creates an acidic environment (pH3) in the stomach.

Mucus (in Stomach)

Protects the wall of the stomach from acid and pepsin.

Bile

Produced by the liver, stored in the gallbladder, and released into the small intestine to neutralize stomach acid and emulsify fats.

Pancreatic and Intestinal Juices

Released into the small intestine, containing amylase, protease, and lipase.

Amylase (Small Intestine)

Completes the digestion of starch into sugars.

Protease (Small Intestine)

Completes the digestion of proteins into amino acids.

Lipase

Breaks down fats into fatty acids and glycerol.

Respiration

The process of transferring energy from food molecules in every living cell.

Aerobic Respiration

Respiration that uses oxygen.

Anaerobic Respiration

Respiration that uses no oxygen.

Aerobic Respiration Equation

Glucose + Oxygen → Carbon Dioxide + Water + Energy

Mitochondria

The site of most reactions in respiration; has a highly folded inner surface to increase surface area for enzymes.

Anaerobic Respiration Equation (Humans)

Glucose → Lactic Acid + Small Amount of Energy

Anaerobic Respiration Equation (Yeast)

Glucose → Ethanol + Carbon Dioxide + Energy

Lungs

Located in the thorax, protected by the ribcage, and separated from the abdomen by the diaphragm.

Alveoli

Provide a large, moist surface richly supplied with blood capillaries for gas exchange in the lungs.

Ventilation

The movement of air into and out of the lungs.

Inhalation

Ribcage moves out and up, diaphragm flattens, increasing thorax volume and reducing pressure, causing air to enter the lungs.

Exhalation

Ribcage moves down and in, diaphragm moves upwards, reducing thorax volume and increasing pressure, causing air to leave the lungs.

Circulatory System

Transports substances around the body via the heart, blood vessels, and blood.

Heart

An organ, mostly muscle, that pumps blood around the body through two circulation systems: one to the lungs and one to the rest of the body.

Arteries

Carry blood away from the heart to the organs; have thick walls containing muscle and elastic fibers.

Veins

Carry blood away from the organs back to the heart; have thinner walls and often contain valves to prevent back-flow of blood.

Capillaries

Very narrow, thin-walled blood vessels in the organs where substances are exchanged between the blood and cells.

Plasma

The liquid part of the blood, transporting carbon dioxide, soluble products of digestion, and urea.

Red Blood Cells

Transport oxygen from the lungs to the organs; contain haemoglobin and have a biconcave shape.

White Blood Cells

Form part of the body’s defense system against pathogens; produce antibodies and antitoxins, and engulf/digest pathogens.

Diffusion

The spreading of particles of a gas or substance in solution, resulting in net movement from higher to lower concentration.

Osmosis

The diffusion of water from a dilute to a more concentrated solution through a partially permeable membrane.

Villi

Finger-like extensions in the small intestine that provide a large surface area for absorption of nutrients.