Year 11 Human Biology ATAR

Metabolism

The sum of all the chemical reactions that occur within an organism

Catabolism

Metabolic pathways that break down molecules, releasing energy.

Anabolism

Metabolic pathways that construct molecules, requiring energy.

Cellular Respiration Equation

Glucose + Oxygen → Carbon Dioxide + Water + ATP energy

Enzyme

A protein that acts as a biological catalyst to speed up a chemical reaction

Enzyme-substrate complex

When an enzyme binds to its substrate

Active Site

A region on an enzyme that binds to a substrate during a reaction.

Lock and Key Theory

Enzyme's active site (lock) is already in appropriate conformation for the substrate (key) to bind

Substrate easily fits into active site

Glycolosis

Breaking glucose into two molecules of a compound called pyruvate; Creates a net total of 2 ATPs; anaerobic; occurs in cytosol

Krebs Cycle

second stage of cellular respiration; occurs in mitochondria; pyruvate molecules are turned into ATPs;Generates 2 ATPs; aerobic

Electron Transport Chain

Uses the high-energy electrons from the Krebs cycle to convert ADP into ATP; aerobic; Generates 34 ATPs

Epithilial tissue

Tissue composed of layers of closely spaced cells that cover organ surfaces; e.g. skin

Connective Tissue

A tissue that provides support for the body and connects its parts; e.g. blood, cartilage

Muscular Tissue

Long thin tissue that contracts to create movement; e.g. cardiac muscle, skeletal muscle

Nervous Tissue

Tissue that carries info between the brain and other parts of the body; e.g. neurones

Lungs

Two organs, located in the thoracic cavity responsible for breathing

Nasal Cavity

hollow space behind the nose; filters and warms air

Pharynx

throat; passageway for food to the esophagus and air to the larynx

Larynx

passageway for air moving from pharynx to trachea; contains vocal cords

Pleural Membrane

membrane that encloses the lungs within the rib cage

Epiglottis

A flap of tissue that seals off the windpipe and prevents food from entering.

Trachea

Allows air to pass to and from lungs

Ribs

The bones in the chest that protect the heart and lungs.

Bronchi

The passages that direct air into the lungs

Intercostal Muscles

Muscles which move the rib cage during breathing

Cell Membrane

A cell structure that controls which substances can enter or leave the cell.

Alveoli

small sacs within the lungs where gas exchange takes place with the bloodstream

Gas Exchange

The uptake of molecular oxygen from the environment and the discharge of carbon dioxide to the environment; occurs in alveoli

Alveoli Adaptations

→moist lining

→good blood supply

→very thin walls

→enormous surface area

Blood

Connective tissue made of plasma, erythrocytes, leukocytes, and platelets.

Erythrocytes

red blood cells; carry oxygen; is biconcave and contains no nucleus to carry more oxygen

Leukocytes

white blood cells; fight infection

Thrombocytes

platelets; forms blood clots

Plasma

Liquid part of blood; carries nutrients, wastes and bicarbonate (which carries the bulk of Carbon Dioxide)

Pulmonary Circulation

Blood circulates through lungs → Gas exchange occurs → Blood becomes oxygenated

Cytoplasm

A watery materials inside the cell in which the organelles are suspended

Cytosol

Fluid portion of cytoplasm; 70-90% water

Nucleus

Control structure and function of the cell

Nucleolus

Found inside the nucleus and produces ribosomes; composed of RNA

Nuclear Membrane

A highly-porous membrane that separates the nucleus from the cytoplasm

Ribosomes

site of protein synthesis; can be attached to Endoplasmic Reticulum

Endoplasmic Reticulum

Provides a site for chemical reactions; stores and transports molecules

Golgi body

Modifies and packages proteins for secretion

Lysosomes

Filled with enzymes needed to break large molecules

Mitochondria

organelle that is the site of ATP (energy) production

Cilia and Flagella

hairlike structures that extend from the surface of the cell, where they assist in movement

Cytoskeleton

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

Inclusions

Substances that aren't part of the cell but found in the cytoplasm. E.g. Haemoglobin, melanin

Centrioles

Cell organelle that aids in cell division in animal cells only

Fluid Mosaic Model

The currently accepted model of cell membrane structure; where the cell membrane is a mosaic of protein molecules drifting in a fluid bilayer of phospholipids

Cell Membrane Features

→Physical Barrier

→Sensitive

→Supports the Cell

→Monitors what goes in and out

Passive Transport

The movement of substances across a cell membrane without the use of energy by the cell

Active Transport

Energy-requiring process that moves material across a cell membrane against a concentration gradient

Osmosis

Diffusion of water through a selectively permeable membrane

Facilitated Diffusion

The transport of substances through a cell membrane along a concentration gradient with the aid of carrier and channel proteins

Endocytosis

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

Exocytosis

A process by which the contents of a cell vacuole are released to the exterior through fusion of the vacuole membrane with the cell membrane.

Pinocytosis

A type of endocytosis in which the cell ingests extracellular fluid and its dissolved solutes.

Phagocytosis

A type of endocytosis in which a cell engulfs large particles or whole cells

Breathing

movement of air into and out of the lungs (not to be confused with respiration)

Arteries

Blood vessels that carry oxygenated blood away from the heart; thick, elastic, small lumen, no valves, have a pulse

Veins

Blood vessels that carry deoxygenated blood back to the heart; has less smooth muscle, valves to prevent back flow; lower blood pressure

Hepatic Portal Vein

The vein that collects blood from the Gastro-Intestinal Tract and conducts it to the liver

Renal Vein

blood vessel that carries blood away from the kidney and toward the heart

Renal Artery

blood vessel that carries blood to the kidney

Capillaries

The smallest vessels where materials are exchanged between the blood and body cells.

Peritubular Capillaries

The network of tiny blood vessels that surrounds the proximal and distal tubules in the kidney

Tricuspid Valve

valve between the right atrium and the right ventricle

Bicuspid Valve

valve between the left atrium and the left ventricle.

pulmonary valve

valve positioned between the right ventricle and the pulmonary artery

aortic valve

heart valve between the left ventricle and the aorta

Systemic Circulation

→Blood circulates through body

→ Nutrients and Oxygen given to cells & waste products are collected

→ Blood becomes deoxygenated

Systole

Contraction of the heart; pumping phase

Diastole

Relaxation of the heart; filling phase

Atrial Systole

Atria contract

→ Atrioventricular valves open

→ blood forced from atria to ventricles

→ Semilunar valves shut

Ventricular Systole

Ventricles contract

→ Semilunar valves open

→ Blood forced from ventricles to arteries

→ Atria are relaxed

→ Atrioventricular valves shut

→ Atria refills with blood

Atrial and Ventricular Systole

Atria and Ventricles relax

→Semilunar valves shut

→Atrioventricular valves open

→Atria refilling with blood

→Ventricles receive blood from atria

Lymph

Excess tissue fluid carried by lymphatic vessels

Lymph Capillaries

microscopic vessels that draw lymph from tissues to the lymph vessels

Lymph Nodes

Bean-shaped filters that cluster along the lymphatic vessels of the body; also called l____ glands

Carbohydrates

The starches and sugars present in foods

Carbohydrate Digestion

Carbohydrate → Polysaccharides → Disaccharides → Monosaccharides

Protein

A compound made of small carbon compounds called amino acids; used for structural support, storage, transport;

Protein Digestion

Protein → Polypeptide → Peptide → Amino Acid

Lipid

Macromolecule made mostly from carbon and hydrogen atoms; includes fats and oils

Lipid Digestion

Lipid → Fatty acids & Glycerol

Mouth Cavity

Place where food enters ;mechanical digestion by teeth; chemical digestion of starch by saliva

Salivary Glands

Glands of the mouth that produce saliva

Saliva

Digestive juice produced by salivary glands; contains amylase and mucus

Oesophagus

Muscular tube connecting the mouth to the stomach; uses peristalsis to move bolus to the stomach

Stomach

Large muscular sac that continues the mechanical and chemical digestion of food

Gastric Juice

A digestive fluid secreted by the stomach; contains HCl and gastric protease

Pyloric Sphincter

Ring of muscle that guards the opening between the stomach and the duodenum

Duodenum

First part of the small intestine

Liver

Produces bile; performs deamination; detoxifies alcohol & drugs

Gall Bladder

Stores bile and releases it as needed into the small intestine

Bile

Emulsifies (increases surface area of) fats; neutralises HCl from the stomach

Pancreas

Produces pancreatic juice

Pancreatic Juice

Contains pancreatic protease, amylase, lipase and nuclease; used for digestion in the duodenum

Small Intestine

Secretes intestinal juice; absorbs simple sugars, amino acids and glycerol