IB Biology: Carbohydrates and Lipids

Carbohydrates

Organic compounds made of carbon, hydrogen, oxygen.

Monosaccharides

Single sugar molecules, basic carbohydrate units.

Pentose Sugars

Monosaccharides with five carbon atoms.

Hexose Sugars

Monosaccharides with six carbon atoms.

Ribose

Pentose sugar in RNA nucleotides.

Deoxyribose

Modified ribose lacking one oxygen atom.

Glucose

Primary energy source for cellular respiration.

Isomers

Compounds with the same formula but different structures.

⍺-D Glucose

Isomer of glucose with specific hydroxyl orientation.

ß-D Glucose

Isomer of glucose with different hydroxyl orientation.

Energy Source

Primary function of monosaccharides in cells.

Cellular Respiration

Process of breaking down glucose for ATP.

Hydrophilic

Substance that dissolves easily in water.

Glycosidic Linkage

Bond formed between monosaccharides in carbohydrates.

Disaccharide

Two monosaccharides linked together.

Polysaccharides

Carbohydrate polymers made of many monosaccharides.

Cellulose

Polysaccharide made of ß-glucose subunits.

Starch

Polysaccharide of ⍺-glucose, energy storage in plants.

Glycogen

Highly branched polysaccharide for energy storage in animals.

Amylose

Unbranched form of starch with helical structure.

Amylopectin

Branched form of starch with both linkages.

Energy Storage Polymers

Polysaccharides used for storing energy.

Condensation Reaction

Process linking monomers, releasing water as by-product.

Hydrolysis Reaction

Process breaking down polymers into monomers.

Glycosidic linkages

Covalent bonds linking sugar monomers in polysaccharides.

Starch

Polysaccharide composed of amylose and amylopectin.

Amylose

Linear starch form with 1' - 4' linkages.

Amylopectin

Branched starch form with 1' - 4' and 1' - 6' linkages.

Cellulose

Structural polysaccharide in plant cell walls.

Beta-glucose

Monomer unit of cellulose with alternating arrangement.

Hydrogen bonds

Attractive forces stabilizing cellulose bundles.

Glycoproteins

Proteins with carbohydrate attachments for cell recognition.

Glycosylation

Process of adding carbohydrates to proteins.

Blood group A

Contains type A glycoproteins on red blood cells.

Blood group B

Contains type B glycoproteins on red blood cells.

Blood group AB

Possesses both type A and B glycoproteins.

Blood group O

Lacks A and B glycoproteins on red blood cells.

Hydrophobic properties

Characteristics of lipids that repel water.

Fatty acids

Hydrocarbon chains forming the basis of lipids.

Amphipathic molecules

Molecules with both hydrophobic and hydrophilic regions.

Phospholipids

Lipids forming cell membranes with hydrophilic heads.

Triglycerides

Lipids formed from glycerol and three fatty acids.

Condensation reactions

Chemical reactions forming esters by removing water.

Steroid hormones

Lipids acting as signaling molecules in the body.

Lipoproteins

Protein-coated fat packages for transport in blood.

Cholesterol

Steroid lipid with a polar hydroxyl group.

Ester Linkage

Bond formed between fatty acids and alcohols.

Triglycerides

Three fatty acids linked to glycerol for energy storage.

Phospholipids

Glycerol linked to two fatty acids and phosphate.

Glycolipids

Carbohydrate linked to fatty acids and alcohol.

Simple Lipids

Esters of fatty acids and alcohols, e.g., triglycerides.

Waxes

Fatty acid linked to long-chain alcohol, waterproofing.

Compound Lipids

Esters of fatty acids with additional groups.

Derived Lipids

Produced from hydrolysis of simple or compound lipids.

Fatty Acids

Long hydrocarbon chains found in most lipids.

Saturated Fatty Acids

No double bonds, straight hydrocarbon chains.

Monounsaturated Fatty Acids

One double bond in hydrocarbon chain.

Polyunsaturated Fatty Acids

Multiple double bonds in hydrocarbon chain.

Cis Isomers

Hydrogens on the same side of double bond.

Trans Isomers

Hydrogens on opposite sides of double bond.

Fats

Saturated fatty acids, solid at room temperature.

Oils

Unsaturated fatty acids, liquid at room temperature.

Hydrocarbon Chain

Chain of carbon atoms in fatty acids.

Melting Point

Temperature at which a substance becomes liquid.

Intermolecular Forces

Attractive forces between molecules affecting states.

Energy Storage

Function of triglycerides in living organisms.

Cell Membranes

Phospholipids are key components of cell membranes.

Signalling Molecules

Derived lipids like steroids and prostaglandins.

Ruminant Animals

Produce trans fatty acids, e.g., cows and sheep.

Fatty Acids

Essential for liquid state at body temperature.

Saturated Fats

Solid fats produced by endotherms at higher temperatures.

Cis-Unsaturated Oils

Liquid oils produced by ectotherms in cold environments.

Poly-Unsaturated Fats

Essential fats like omega-3 and omega-6 from cold water fish.

Triglycerides

Energy storage molecules in adipose tissues.

Energy Storage

Triglycerides store twice as much energy as carbohydrates.

Thermal Insulation

Triglycerides provide insulation against cold exposure.

Phospholipids

Key structural components of cell membranes.

Amphipathic

Molecules with both hydrophilic and hydrophobic regions.

Phospholipid Bilayer

Formed by phospholipids shielding hydrophobic tails.

Steroids

Lipids with four fused carbon rings, non-polar.

Steroid Hormones

Signalling molecules that diffuse across cell membranes.

Hydrophobic

Molecules that repel water and do not dissolve.

Carrier Proteins

Transport steroid hormones in the bloodstream.

Cholesterol

Precursor for steroid hormone synthesis.

Subcutaneous Fat

Insulating fat layer in cold-adapted mammals.

Obesity and Heat Stress

Obese individuals retain heat, increasing heat stress risk.

Glycerol

Component of phospholipid polar heads.

Fatty Acid Chains

Non-polar tails of phospholipids.

Hydrophilic Head

Water-loving part of phospholipids.

Hydrophobic Tails

Water-repelling part of phospholipids.

Aquatic Mammals

Have thick fat layers for thermal insulation.

Oestradiol

A type of estrogen, a sex steroid.

Testosterone

A male sex steroid hormone.