IB Biology 2025 (Unit 1(A)) SL

carbon compounds

carbohydrates, lipids, nucleic acid, proteins

Metabolism

the chemical processes (enzyme catalyzed) that occur within a living organism in order to maintain life.

Anabolism

the synthesis of complex molecules in living organisms from simpler ones, including ther formation of macrolmes from monomers by condensation reactions

Catabolism

the breakdown of complex molecules into simpler molecules, including the hydrolysis of macromolecules into monomers.

Subcomponent of carbohydrates

monosaccharides

subcomponent of lipids

Glycerol, fatty acids, phosphate groups

Subcomponent of proteins

amino acids

Protein examples

enzymes, antibodies, peptide hormones

Monosaccharide examples

glucose, fructose, galactose, ribose, deoxyribose

Disaccharide examples

sucrose, lactose, maltose

polysaccharide examples

starch, glycogen, cellulose, chitin

phospholipid example

bilayer of cell membrane

Steroid examples

cholesterol, testosterone, estrogen

hydrogen bond

Attraction between a slightly positive hydrogen atom and a slightly negative atom.

polar covalent bond

bond between the oxygen atom and the two hydrogen atoms of a signle water molecule; A covalent bond in which electrons are not shared equally

Electrons

Negatively charged particles

covalent bond

A chemical bond formed when two atoms share electrons

Cohesion

Attraction between molecules of the same substance

Adhesion

An attraction between molecules of different substances

high specific heat capacity

A property of water. Water can absorb lots of heat before changing temperature

Hydrophilic

water loving

Hydrophobic

Water fearing

monosachharides

monomer of carbohydrates; linked together by condensation reactions to form disaccharides

Types of fatty acids

saturated, monounsaturated, polyunsaturated

Triglycerides

formed by condensation from three fatty acids and one glycerol

condensation reaction

Cellulose

major component of cell walls, helps give rigidity support to roots, stems, and leaves

Starch

A storage polysaccharide in plants consisting entirely of glucose; usually located in roots

Glycogen

Storage form of glucose in animals; usually located in liver and muscle tissue

saturated fatty acid

carbons are saturated with hydrogen atoms; generally solid at room temperature; no double bonds

monounstaturated fatty acids

one double bond exists in the chain of a hydrocarbon; cause one "kink" or bend in the molecule

polyunsaturated fatty acid

two or more double bonds in the carbon chain; usually liquid at room temperature

cis fatty acids

Two covalent single C-C bonds angle in the same direction adjacent to the C=C double bond

trans fatty acids

fatty acids with hydrogens on opposite sides of the double bond

amino acids

a simple organic compound containing both a carboxyl (—COOH) and an amino (—NH2) group; linked together by condensation to form polypeptides.

Ribosomes

site of protein synthesis; amino acid linkage

peptide bond

The chemical bond that forms between the carboxyl group of one amino acid and the amino group of another amino acid

Enzymes

proteins that act as biological catalysts; speed up chemical reactions that take place in cells by lowering the activation energy; act on specific substrates

Denature

destroy the characteristic properties of (a protein or other biological macromolecule) by heat, acidity, or other effects that disrupt its molecular conformation.

Organelle

A tiny cell structure that carries out a specific function within the cell

Compartmentalization

Membrane-bound organelles allow different parts of the cell to perform different functions at the same time

stem cells

unspecialized cells that are able to renew themselves for long periods of time by cell division

Pluripotent

Cells that are capable of developing into most, but not all, of the body's cell types

totipotent

Stem cells with the potential to differentiate into any type of cell.

Multipotent

cell with limited potential to develop into many types of differentiated cells

stem cell niche

an area of a tissue that provides a specific microenvironment, in which stem cells are present in an undifferentiated and self-renewable state.

surface area to volume ratio

a variable that decreases as cells grow, so that it sets a limit to the size of cells.

Phopholipids

A glycerol linked to a phosphate group and to two fatty acids

amphipathic

having both a hydrophilic region and a hydrophobic region

Differentiation

process in which cells become specialized in structure and function