1.1: Chemical elements and biological compounds (copy) (copy) (copy)

Inorganic ions

Ions without carbon.

Organic ions

Ions with carbon.

Micronutrients

Needed in minute (trace) concentrations.

Macronutrients

Needed in small concentrations.

Calcium

A main constituent in bones, teeth and shells.

Chlorine

Necessary to maintain electrical neutrality across membranes.

Iron

Necessary for healthy red blood cells.

Magnesium

Essential in photosynthesis.

Nitrate

Component of enzymes, amino acids, proteins, vitamins, etc.

Phosphate

Component of DNA, RNA, ATP, phospholipids, and nucleotides.

Potassium

A factor in protein synthesis and respiration.

Sodium

Needed to maintain active transport across cell membranes, and electrical balance.

Sulphate

Forms bridges between polypeptide chains.

Dipole

A molecule with one end having a partial negative charge and the other end having a partial positive charge; a polar molecule.

Polar molecule

A molecule with different charges.

Delta

Symbol to show partial charge.

Hydrogen bonds

Weak attraction between a hydrogen atom and another atom.

Water cohesion

Water molecules stick to each other, creating strong bonds.

Solvent

A liquid substance capable of dissolving other substances.

Hydrolysis

Breaking down a compound by the chemical addition of water.

Metabolite

Involved in chemical reactions in the body.

High latent heat capacity

The term for: 'a lot of heat energy is needed to change water between states'.

High surface tension

What allows insects to float on the surface of water.

Monosaccharide

A single sugar molecule such as glucose or fructose, the simplest type of sugar.

Disaccharide

Two monosaccharide molecules that join together - table sugar.

Polysaccharides

Carbohydrates that are made up of more than two monosaccharides.

Carbohydrate

Organic compounds composed of carbon, hydrogen, and oxygen.

Isomers

Two different molecules that have the same chemical formula.

Polymers

Large compound formed from combinations of many monomers.

Glycosidic bond

Bond formed by a condensation reaction between two monosaccharides.

Benedict's test

Test for reducing sugars, done by heating the solution and adding an equal amount of the test solution.

Qualitative test

Analyzes for the presence or absence of substances.

Sucrose

Table sugar.

Quantitative test

Analysis that can identify quantity or actual number counts such as counting the number of blood cells.

Biosensor

A device that uses biological molecules to measure the level of certain chemicals.

Maltose

Glucose + glucose: used in germinating seeds.

Lactose

Glucose + galactose: in mammalian milk.

Xylem vessels

Transports water and minerals through the plant, also supports the plant.

Starch

A storage polysaccharide in plants consisting entirely of glucose.

Amylopectin

Branched starch.

Amylose

Unbranched starch.

Glycogen

Storage form of glucose in animals - branched.

Cellulose

Carbohydrate component of plant cell walls, forms crosslinks between other layers.

Chitin

Polysaccharide found in arthropod exoskeletons and fungal cell walls, with amino acids added.

Microfibrils

Cellulose and chitin chains linked by hydrogen bonds form these strong fibres.

Fibres

Made of microfibrils held together in bundles by hydrogen bonding.

Heteropolysaccharide

A polymer made up of more than one type of monosaccharide.

Iodine-potassium iodine test

Tests for presence of starch, done by adding the test solution.

Ribose

Sugar found in RNA.

Glucose

A simple sugar that is an important source of energy.

(CH2O)n

General formula for carbohydrates.

Proteins

Contain carbon, hydrogen, oxygen and nitrogen.

N-terminal

Amino end of a polypeptide.

C-terminal

Carboxyl end of a polypeptide.

R group

A functional group that defines a particular amino acid and gives it special properties.

Zwitterion

A molecule that contains charges, but is neutral overall. Most often used to describe amino acids.

Peptide bond

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

Primary structure

Sequence of amino acids.

Secondary structure

The second level of protein structure; beta pleated sheet or alpha helix.

B-pleated sheet

Two regions of the chain lie parallel to each other and are held together by hydrogen bonds, a form of the secondary structure.

A-helix

The chain is twisted into spirals, and is held by hydrogen bonds, a form of the secondary structure.

Tertiary structure

The third level of protein structure; the overall, three-dimensional shape of a polypeptide due to interactions of the R groups of the amino acids making up the chain.

Disulphide bonds

Strong bonds between amino acids with sulphur, a covalent bond.

Hydrophobic interactions

Grouping of hydrophobic molecules grouping together to avoid water.

Quaternary structure

The fourth level of protein structure; the shape resulting from the association of two or more polypeptide subunits.

Fibrous proteins

Long, insoluble, structural proteins.

Collagen

Fibrous protein that gives the skin form and strength.

Globular protein

A type of protein that is compact, folded into spherical molecules, soluble in water.

Haemoglobin

Globular protein that combines with oxygen to move it around the body.

Biuret test

Test for proteins, done by adding the test solution to a solution.

Purple

Positive test for biuret.

Enzymes

Globular proteins that act as biological catalysts.

Salt bridge

An ionic bond in a protein, holds the polypeptide chain together.

Monounsaturated

One double bond in a lipid.

Polyunsaturated

Two or more double bonds in a lipid.

Emulsion test

Test for lipids, by adding alcohol and checking for a milky white emulsion.

**Brick red**

Colour a solution turns if positive for reducing sugars during a Benedict’s test.

Blue-black

Colour a solution turns if positive for starch during an iodine-potassium iodine test.