SBI4U Review

Ionic Bonds

Transfer of electrons between atoms with high electronegativity.

Cation

Positively charged ion formed from electron loss.

Anion

Negatively charged ion formed from electron gain.

Covalent Bonds

Sharing of electrons between atoms.

Polar Covalent Bonds

Unequal sharing of electrons; results in partial charges.

Nonpolar Covalent Bonds

Equal sharing of electrons; no partial charges.

Amphiphilic Molecules

Molecules with both polar and nonpolar parts.

Electronegativity

Atom's ability to attract electrons in a bond.

Hydrogen Bonds

Attraction between partially charged hydrogen and another atom.

Van der Waals Forces

Weak attractions between molecules due to momentary dipoles.

Dehydration Reaction

Joins molecules by removing water (OH and H).

Hydrolysis Reaction

Splits molecules by adding water (OH and H).

Neutralization Reaction

Reaction between acids and bases forming water and salt.

Redox Reaction

Transfer of electrons; oxidation and reduction processes.

Cohesion

Attraction between water molecules due to hydrogen bonds.

Adhesion

Attraction between water molecules and other polar substances.

Capillary Action

Movement of water in narrow spaces due to adhesion and cohesion.

Surface Tension

Increased bond strength at the water's surface.

Lower Density Solid

Ice is less dense than liquid water, allowing floating.

High Heat of Vaporization

Energy required to convert water from liquid to gas.

High Heat Capacity

Water requires large heat amounts to change temperature.

Universal Solvent

Water dissolves ionic and polar substances effectively.

Functional Groups

Specific groups of atoms that determine molecular behavior.

Glucose

A simple sugar with formula C6H12O6.

Fructose

A monosaccharide found in many plants.

Disaccharides

Two monosaccharides linked by glycosidic bonds.

Condensation Reaction

Combines monosaccharides, releasing H2O.

Hydrolysis

Uses H2O to break down disaccharides.

Glycosidic Bond

Linkage between monosaccharides in carbohydrates.

Polysaccharides

Long chains of monosaccharides for storage or structure.

Cellulose

Structural polysaccharide in plant cell walls.

Chitin

Polysaccharide forming arthropod exoskeletons.

Glycogen

Storage polysaccharide in animals, mainly glucose.

Leukoplasts

Organelles storing starch in plant roots.

Hydroxyl Group

Functional group -OH, found in carbohydrates.

Carboxyl Group

Functional group -COOH, found in fatty acids.

Triglycerides

Fats composed of glycerol and three fatty acids.

Ester Bond

Linkage between glycerol and fatty acids.

Omega-3 Fatty Acids

Essential fats with a double bond at carbon 3.

Phospholipids

Molecules forming cell membranes with hydrophilic heads.

Covalent Bonds

Strong bonds formed by sharing electron pairs.

Amino Acids

Building blocks of proteins, 20 types exist.

Dipeptides

Two amino acids linked by peptide bonds.

Enzymes

Proteins that catalyze biochemical reactions.

Primary Structure

Sequence of amino acids in a polypeptide.

Tertiary Structure

3D shape of a protein due to folding.

Denaturation

Loss of protein function due to structural changes.

Prokaryotic Cells

Simple cells without a nucleus, e.g., bacteria.

Eukaryotic Cells

Complex cells with membrane-bound organelles.

Rough ER

Produces insulin in pancreatic cells.

Cell Membrane

Maintains shape and regulates entry/exit.

Fluid Mosaic Model

Describes flexible membrane structure with embedded proteins.

Phospholipids

Form bilayer with hydrophilic heads and hydrophobic tails.

Carbohydrates

Cell markers for identity and immune recognition.

Glycoproteins

Cell markers that are person-specific.

Glycolipids

Tissue-specific markers preventing excessive cell growth.

Cholesterol

Regulates membrane fluidity at varying temperatures.

Globular Proteins

Function as receptors, transporters, and enzymes.

Integral Proteins

Embedded proteins within the cell membrane.

Peripheral Proteins

Surface-attached proteins on the membrane.

Fibrous Proteins

Form cytoskeleton to maintain cell shape.

Passive Transport

Diffusion from high to low concentration.

Osmosis

Diffusion of water across a membrane.

Simple Diffusion

Movement of small nonpolar molecules across membranes.

Facilitated Diffusion

Requires protein channels for large polar molecules.

Hypotonic Solution

Lower solute concentration; can cause cell bursting.

Hypertonic Solution

Higher solute concentration; causes cell shrinkage.

Isotonic Solution

Equal solute concentration; achieves equilibrium.

Active Transport

Movement against concentration gradient using ATP.

Carrier Proteins

Change shape to transport substances using ATP.

Endocytosis

Membrane folds to bring substances into the cell.

Exocytosis

Vacuoles release substances outside the cell.

Enzyme

Biological catalyst speeding up reactions without consumption.

Active Site

Pocket in an enzyme binding to a substrate.

Substrate

Substance recognized and bound by an enzyme.

Anabolic Enzyme

Enzyme that pulls molecules together.

Catabolic Enzyme

Enzyme that pulls molecules apart.

Induced-Fit Hypothesis

Enzymes change shape to fit substrates better.

Enzyme-Substrate Complex

Temporary complex formed when enzymes bind substrates.

Activation Energy

Energy needed to start a chemical reaction.

Cofactors

Non-protein molecules required for enzyme activity.

Coenzymes

Vitamins-derived molecules acting as electron carriers.

Temperature Effect

Low temperatures cause enzyme inactivity; high denatures.

pH Effect

Enzymes have optimal pH; extremes cause denaturation.

Concentration Effect

Enzymes have a maximum rate of substrate breakdown.

Competitive Inhibitors

Molecules blocking substrates by binding to active site.

Non-Competitive Inhibitors

Molecules altering enzyme shape, affecting active site.

Metabolism

Chemical processes converting food to energy.

First Law of Thermodynamics

Energy cannot be created or destroyed, only transformed.

Second Law of Thermodynamics

Energy transfers lose some energy as heat.

ATP

Energy currency of the cell, consisting of ribose.

Mitochondria

Cell organelles where cellular respiration occurs.

Cristae

Folds in inner membrane increasing mitochondrial surface area.

Mitochondrial DNA

DNA inherited maternally, from the egg cell.

Mitochondrial Eve

Common ancestor of all modern humans.

Mitochondrial DNA

Inherited maternally, traces lineage through mothers.

Aerobic Cellular Respiration

Process using oxygen to produce ATP.

C6H12O6 + 6O2 → 6CO2 + 6H2O + 36ATP

Chemical equation for aerobic respiration.

Cytoplasm

Location of glycolysis in the cell.

Mitochondria

Site of Kreb's Cycle and ETC.