IB Biology B1.1 - Carbs & Lipids

SI Units

Used to ensure scientists from different parts of the world have the same standard system of measurements.

Carbohydrates

A group of organic compounds that typically contain hydrogen and oxygen at a 2:1 ratio & are usually easily utilised by cells for energy.

Lipids

A diverse range of hydrophobic, organic compounds which all have chains of hydrocarbons.

Covalent Bonds

Bonds between atoms where electrons are shared.

Macromolecules

Large molecules eg. Carbohydrates, lipids, Proteins.

Monomers

One of Something - a molecule that can be joined with other similar molecules to make a polymer.

Polymers

Many of Something - a molecule made of many similar monomers joined together.

Polysaccharides

"Many sugars" - Polymers of carbohydrates.

Polypeptides

"Many peptides" - Polymers of amino acids (protein).

Nucleic Acids

Composed of a pentose sugar, nitrogenous base and phosphate. E.g. DNA, RNA.

Condensation Reactions

Reactions in which a bond is formed and water is also produced.

Hydrolysis Reactions

Reactions in which a bond is broken using water ("water cutting").

Monosaccharides

"One Sugar" - Monomers of carbohydrates.

Pentose Sugars

Sugars with 5 carbons.

Hexose Sugars

Sugars with 6 carbons.

Starch

Polysaccharide used for energy storage in plants.

Amylose

Form of starch that is linear (no branches).

Amylopectin

Form of starch that is branched.

Cellulose

Polysaccharide used for structure in plants, especially in cell walls.

Glycogen

Polysaccharide used for energy storage in animals.

Cellulose Microfibrils

A cluster of polymers of cellulose joined together with hydrogen bonds.

Glycoproteins

Found in the membrane of cells. Proteins with a carbohydrate attached. used for cell recognition, communication & adhesion.

Antigens

Substances which stimulate an immune response and the production of antibodies. Used as identifiers to tell if a cell belongs.

Amphipathic

Has both polar and non-polar parts.

Hydrophobic

"Scared of water" - Non polar substance that will not dissolve or mix with water.

Hydrophilic

"Water lover" - Polar or charged substance that will dissolve or mix with water.

Triglycerides

Polymer of lipids formed from 1 glycerol & 3 fatty acids.

Phospholipids

Type of lipid used in plasma membranes. composed of 1 glycerol, 2 fatty acids & 1 phosphate group.

Fatty Acids

A long chain of carbon and hydrogen ending in a carboxyl (-COOH) group.

Saturated Fatty Acids

Fatty acids where all carbon-carbon bonds are single bonds.

Unsaturated Fatty Acids

Fatty acids where at least 1 carbon-carbon bond is a double bond.

Monounsaturated Fatty Acids

Fatty acids where exactly 1 carbon-carbon bond is a double bond.

Polyunsaturated Fatty Acids

Fatty acids where many carbon-carbon bonds are double bonds.

Steroids

Lipids with four carbon rings and a hydrocarbon chain.

Fats

Triglycerides which are solid at room temperature, with relatively high melting points. The fatty acids are usually saturated.

Oils

Triglycerides which are liquid at room temperature, with relatively low melting points. The fatty acids are usually unsaturated.