Cell Biology and Chemistry

Secretory Vesicle

A membrane pouch that transports proteins and hormones from the Golgi apparatus to the cell membrane to be released outside.

Nucleus

A double-membrane organelle that stores the cell's DNA and controls cellular activities like growth, metabolism, and protein synthesis.

Nuclear Membrane

A double-layered barrier that surrounds the nucleus, protecting its DNA and controlling what enters or exits through tiny nuclear pores.

Nucleolus

A dense region inside the nucleus that produces ribosomal RNA (rRNA) and assembles the subunits needed to build ribosomes.

Rough Endoplasmic Reticulum (RER)

A network of folded membranes studded with ribosomes that folds, modifies, and transports proteins produced by those ribosomes.

Ribosome

A tiny organelle made of RNA and protein that reads mRNA sequences to synthesize proteins for the cell.

Golgi Body

A stack of flattened membrane sacs that modifies, sorts, and packages proteins and lipids into vesicles for transport inside or outside the cell.

Cell Membrane

A flexible barrier made of a phospholipid bilayer that encloses the cell, regulating what enters and exits to maintain internal balance.

Microfilament

A thin thread of actin protein that gives the cell structural support, helps maintain its shape, and enables cell movement.

Flagellum

A long, whip-like appendage that projects from the cell surface and rotates or lashes to propel the cell forward.

Microvilli

Tiny, finger-like projections on the cell surface that increase surface area to maximize the absorption of nutrients and materials.

Mitochondria / Mitochondrion

Responsible for converting nutrients and oxygen into cellular energy (ATP) to power cell processes.

Lysosome

A membrane-bound organelle containing digestive enzymes that breaks down cellular waste, debris, and foreign invaders.

Smooth Endoplasmic Reticulum (SER)

A network of tubular membranes without ribosomes that synthesizes lipids, metabolizes carbohydrates, and detoxifies harmful substances in the cell.

Define what an element is

A pure substance made up of only one type of atom that cannot be broken down chemically into anything simpler, and is composed of a nucleus and electrons.

Define what a compound is

A pure substance composed of two or more different elements chemically bonded together in a fixed ratio.

Define what a mixture is

A physical blend of two or more substances that retain their individual chemical identities and can be separated by physical means.

Nervous Tissue

Conducts electrical impulses throughout the body to enable communication, processing, and regulation of bodily functions.

Epithelial Tissue

Covers body surfaces and lines organs to provide protection, absorption, secretion, filtration, and sensation.

Muscle Tissue

Contracts and relaxes to generate physical movement, maintain posture, and produce body heat.

Connective Tissue

Provides structural support, protection, insulation, and transportation by connecting and anchoring different organs and tissues.

Sensory neuron

Detects stimuli from the internal or external environment and transmits those signals directly toward the central nervous system.

Motor Neuron

Carries nerve signals from the brain and spinal cord to muscles and glands to trigger movement and physiological responses.

Interneuron

Acts as an information bridge within the central nervous system, connecting sensory and motor pathways to process complex signals like memory, learning, and planning.

What does the symbol O represent

Oxygen (Constituent of water and organic molecules; necessary for cellular respiration)

What does the symbol C represent

Carbon (Found in every organic molecule)

What does the symbol H represent

Hydrogen (Constituent of water and most organic molecules)

What does symbol N represent

Nitrogen (Constituent of all protein molecules)

What does symbol P represent

Phosphorus (Constituent of many protein molecules, ATP; required for normal bone and teeth)

What does symbol Ca represent

Calcium (Present as calcium ions in bone and teeth; required for blood clotting)

What does symbol Cl represent

Chlorine (Present as chloride ions in extracellular fluid)

What does symbol S represent

Sulphur (Constituent of many proteins)

What does symbol Na represent

Sodium (Present as sodium ions in extracellular fluid; essential in maintaining water balance)

What does symbol K represent

Potassium (Present as potassium ions in intracellular fluid; required in conduction of nerve impulses)

What does symbol Mg represent

Magnesium (A cofactor for many enzymes)

What does symbol Fe represent

Iron (Oxygen binding component of haemoglobin)

What does symbol I represent

Iodine (Vital to functioning of thyroid)

What is a compound

A pure substance that contains two or more elements chemically bonded

Inorganic compounds

Usually small molecules that lack carbon (e.g., water, carbon dioxide, salts, acids, bases).

Organic Compounds

Always contain carbon (C) and can be made by living things (e.g., carbohydrates, lipids, proteins, nucleic acids).

Chemical formula

A shorthand way of representing a chemical compound that shows the elements present and their proportions.

characteristic properties of metals that distinguish them from non-metals

High conductivity, shiny, almost all solid, conduct heat & electricity and is malleable.

Name the region of the brain responsible for learning

Cerebrum

What is a mixture?

Two or more substances (elements/compounds) mixed in any proportion that keeps their own properties.

What does solute mean

The substance being dissolved

What does solvent mean

The substance doing the dissolving

Properties of a solution

Always clear (even if coloured); solute does not settle out and cannot be filtered out. Eg. salt water, vinegar, air, sugar water.

Type of mixture: colloid

Particles too small to see but big enough to diffract light, cannot pass through semi-permeable membranes. Eg, milk, fog gelatin, blood plasma, mayo

Type of mixture: suspension

Very small but visible particles of a solid suspended in a liquid. Eg, whole blood, muddy water, OJ with pulp

Type of mixture: Emulsion

Droplets of one liquid suspended in another liquid eg, milk, butter, mayo, oil

Bile salts

Acts as emulsifiers to allow the dispersion of fats in the intestine.

body solutions

Fluids containing dissolved solutes (glucose, salts, urea) essential for physiological function.

Primary solvent

Water H20 - the most important solvent in the human body

Hydrophilic

Water loving

Hydrophobic

Water hating

What of these are elements

Iodine, carbon

What of these are compounds

Sodium chloride (NaCl), haemoglobin, distilled water, magnesium oxide (MgO), Glucose (C6H12O6)

What of these are Mixtures

Milk, air, blood, urine blood plasma

How many atoms of each element are in this? CO2

1 carbon, 2 Oxygen

How many atoms of each element are in this? H2

2 Hydrogen

How many atoms of each element are in this? NH4CL

1 Nitrogen, 4 Hydrogen, 1 Chlorine

How many atoms of each element are in this? Fe(OH)2

1 iron, 2 oxygen, 2 hydrogen

How many atoms of each element are in this complex molecule? C6H12O6

6 carbon, 12 Hydrogen, 6 Oxygen

How many atoms of each element are in this complex molecule? Mg(HCO3)2

1 magnesium, 2 hydrogen, 2 carbon, 6 Oxygen

How many atoms of each element are in this complex molecule? (NH4)3PO4

1 nitrogen, 12 Hydrogen, 1 Phosphorus, 4 Oxygen

How many atoms of each element are in this complex molecule? NaH2PO4

1 Sodium, 2 Hydrogen, 1 phosphorus, 4 Oxygen

What type of mixture is found in whole blood?

Suspension and Colloid

What type of mixture is found in blood plasma?

Solution and Colliod

What are 3 key physical properties of metals that distinguish them from non-metals?

Conductivity, malleability & ductility, and luster (shiny appearance)

What are the main two branches that matter is divided into?

Pure substances and mixtures

What are examples of pure substances?

Gold, pure water, oxygen, table salt

What are examples of Mixtures

Air, milk, blood, saline solution

What two categories fall under pure substances

Elements and compounds

What are some elements?

Carbon, iron, hydrogen, nitrogen

What are some compounds?

Water (H2O), carbon dioxide (CO2), sodium chloride (NaCl), glucose (C6H12O6)

What two subcategories do elements divide into

Metals and non-metals

What are some examples of metals?

Iron, magnesium, calcium, potassium, copper

What are some examples of Non-metals

Oxygen, carbon, nitrogen, chlorine, iodine

What is a chemical change?

Makes or breaks compounds into elements ( eg. electrolysis)

What is a physical change?

Changes state ( solid, liquid, gas); molecules stay the same

What is electrolysis

Using electric current to break down a compound into elements.

What is sublimation?

Direct change from solid to gas. (Eg. Dry ice/solid CO2)

Why does sweating cool the body?

Evaporation, sweat absorbs body heat to change into gas, pulling thermal energy away from the skin.

Physical change features

No new substance, easily reversed, retains properties.

Chemical change features

New substance formed, hard to reverse, new properties

Physical change examples

Freezing/boiling water, dissolving sugar/salt, evaporating sweat, melting wax, blood dialysis/separation, sublimating dry ice

Chemical change examples

Rising bread dough, grape fermentation, rusting metal, burning candles, souring milk, electrolysis of water

Heated iodine

Greyish solid turns to purple gas (sublimation-physical change)

Cooling iodine

Purple gas turns back into solid (deposition/reverse sublimation)

Heating sucrose (physical)

Sucrose melts into clear liquid (reversible state change)

Heating sucrose (chemical)

Continuous heat thermally decomposes sugar into black carbon, steam, and bubbles (irreversible)

Burning magnesium ribbon (reaction and balanced equation)

Malleable metal burns with bright white light, leaving white powder MgO. Equation: 2mG + O2 → 2MgO

Subatomic Particles contain

Protons, electrons, and neutrons

Properties of proton

Nucleus, +1, relative mass 1

Properties of electron

Around nucleus, -1, relative mass negligible

Properties of neutron

Nucleus, 0, relative mass 1

What determines an atoms mass

Almost all mass is in the nucleus (protons + neutrons)

What determines an atoms Volume/size

Determines by the electron cloud (space electrons move around in)

Atomic number

Number of protons (also equals number of electrons in a neutral atom). Defines the element

Mass number

Total number of particles in the nucleus (protons + neutrons)