Human Biology Yr11 ATAR

Why are cells so small?

Why are cells so small?

To maintain a higher surface area to volume ratio for efficient exchange of nutrients and waste.

Cell membrane composition

Composed of phospholipid bilayer that regulates passage of substances.

Function of proteins in the cell membrane

Transport substances and recognition during cell signaling.

Cytoplasm

Site of many cellular processes, composed mostly of water, proteins, salts, and organic molecules.

Function of mitochondria

Powerhouse of the cell, responsible for ATP production through oxidative phosphorylation.

Structure of mitochondria

Contains a double membrane with inner folds called cristae.

What is the rough endoplasmic reticulum (RER) involved in?

Site of protein synthesis with ribosomes attached.

Function of smooth endoplasmic reticulum (SER)

Lipid synthesis and detoxification.

What are vesicles?

Transport materials within the cell, types include endocytic and exocytic.

Function of the Golgi body

Modifies, sorts, and packages proteins.

Function of lysosomes

Digestion and recycling of cellular waste.

What are vacuoles used for?

Storage, waste disposal, and structural support.

What is the function of the nucleus?

Contains genetic material (DNA) and regulates cell activities.

Nuclear membrane function

Separates nucleus from cytoplasm and regulates passage of molecules.

Nucleolus function

Ribosome biogenesis and processing of RNA.

Centrosomes and centrioles

Play roles in cell division and organize microtubules.

Fluid Mosaic Model introduction

Describes the structure of cell membranes composed of a phospholipid bilayer.

Definition of diffusion

Movement of particles from high to low concentration.

Facilitated diffusion

Passive transport requiring carrier proteins to move molecules across membranes.

What is osmosis?

Movement of water across a semi-permeable membrane from low to high solute concentration.

What is active transport?

Movement of molecules against their concentration gradient, requiring energy.

What is vesicular transport?

Packaging of large molecules into vesicles for transport across membranes.

Endocytosis definition

Process of a cell taking in molecules by engulfing them in a vesicle.

Exocytosis definition

Process of a cell releasing molecules by fusing vesicles with the cell membrane.

Surface area to volume ratio importance

Higher ratios enhance nutrient and waste exchange, aiding in homeostasis.

Factors affecting substance movement across membranes

Concentration gradient, size of molecules, charge, and temperature.

What is cellular respiration?

Process by which cells generate energy from glucose.

Anaerobic respiration

Respiration without oxygen.

Aerobic respiration

Respiration that requires oxygen.

Key steps in cellular respiration

Glycolysis, Krebs cycle, and electron transport chain.

Purpose of enzymes

Biological catalysts that regulate biochemical reactions.

What are anabolic reactions?

Building complex molecules from simpler ones, requiring energy.

What are catabolic reactions?

Breaking down complex molecules into simpler ones, releasing energy.

Important factors affecting enzyme activity

pH, temperature, inhibitors, and concentration of substrates.

Components of the cytoskeleton

Microfilaments, intermediate filaments, and microtubules.

Function of epithelial tissue

Covers body surfaces and lines internal organs.

Function of connective tissue

Provides support and structure to the body.

Function of muscular tissue

Enables movement and generates force.

Key function of nervous tissue

Transmits electrical signals in the body.

Light microscopy

Uses visible light to illuminate samples.

Electron microscopy

Uses a beam of electrons to view tiny structures.

What is the role of cholesterol in cell membranes?

Helps regulate membrane fluidity and stabilizes membrane structure.

Blood components

Plasma, erythrocytes, leukocytes, and platelets.

Blood clotting process

Vasoconstriction, platelet plug formation, and coagulation.

Function of erythrocytes

Transport oxygen using hemoglobin.

Function of leukocytes

Defend against infections and foreign invaders.

Function of platelets

Assist in blood clotting during injuries.

What is the role of the lymphatic system?

Return tissue fluid to circulatory system and help fight disease.

Kidney function

Regulate chemical composition of body fluids by removing wastes.

Structure of the nephron

Functional unit of the kidney involved in filtration and urine formation.

What is deamination?

Process of removing amine group from amino acids in the liver.

Function of the liver

Processes and detoxifies substances in blood from digestive organs.

What is the role of the digestive system?

Break down food and absorb nutrients.

What is protein synthesis?

Process of building proteins based on genetic information.

Role of RNA in protein synthesis

Carries genetic code from DNA to ribosomes.

Meiosis definition

Type of cell division that produces haploid gametes.

What is the major difference between mitosis and meiosis?

Mitosis produces two diploid cells; meiosis produces four haploid gametes.

Oogenesis definition

Process of egg formation in females.

Spermatogenesis definition

Process of sperm cell development in males.

Hormonal control in menstruation

Regulated by hormones like estrogen and progesterone.

What triggers ovulation?

Surge in luteinizing hormone.

The function of the corpus luteum

Produces progesterone to maintain the uterine lining.

Function of the aorta

Carries oxygenated blood from heart to body.

What is the structure of DNA?

Double helix formed by nucleotides with specific base pairing.

Differences between DNA and RNA

DNA is double-stranded, contains deoxyribose; RNA is single-stranded, contains ribose.

Chromatin definition

Expanded form of DNA within the nucleus.

Antigens and blood groups

Blood groups based on the presence of specific antigens.

Genetic inheritance vs. epigenetic inheritance

Genetic inheritance involves DNA; epigenetic inheritance involves changes in gene expression.

Function of the gastrointestinal tract

Breaks down food mechanically and chemically.

What is peristalsis?

Muscular contractions that move contents through the alimentary canal.

Main function of villi in the small intestine

Increase surface area for nutrient absorption.

Role of bile in digestion

Emulsifies fats for better digestion.

What is the main function of excretory system?

Remove metabolic wastes from the body.

What are nephrons responsible for?

Filtration, reabsorption, and secretion in the kidneys.

What is the function of the rectum?

Stores feces until elimination.

What happens during diastole?

Heart muscle relaxes, allowing chambers to fill with blood.

What happens during systole?

Heart contracts to pump blood out to the body.

Explain the process of translation in protein synthesis.

Ribosomes read mRNA codons to build a polypeptide chain.

What is mitochondrial DNA?

DNA found in mitochondria, distinct from nuclear DNA.

Purpose of transcription in protein synthesis

Copies gene information from DNA to mRNA.