Anatomy and Physiology 12 Unit A

Cell compounds and Biological Molecules

Covalent bond

Chemical bond formed by the sharing of electrons between atoms (eg. CO2 O=C=O)

Ionic bond

Chemical bond formed between oppositely charged ions (eg. NaCl)

Polar

Molecules and molecular bonds where sharing of electrons is unequal (eg. some amino acids)

Dipole

Charge on a polarized molecule, either positive or negative. Positive = less electrons, negative = greater electron presence.

Hydrogen bonds

Weak electrostatic attractions between opposite dipoles (eg. water molecules)

Cohesion

“Sticking together” (eg. water molecules)

Solvent

Portion of a solution that is greater in quantity. Solute is dissolved in this.

Dissociate

To break apart into component ions (eg. HCl will produces H+ and Cl-)

Specific heat capacity

The ability of a substance to retain its temperature while gaining or losing energy (eg. water is high so it takes a lot of energy to change its temperature)

Lubricant

Substance that reduces friction (eg. water is one in the human body)

Transparent

Able to transmit light without much interference (eg. water)

Acid

Substance that promotes a pH of less than 7.0 by releasing H+ (eg. HCl)

Ion

A charged atom, or group of atoms (eg. Na+)

Base

Substance in solution that promotes a pH greater than 7.0 due to the abundance of OH+ (hydroxide) ions (eg. NaOH)

Hydroxide ions

The dissociation of water produces equal numbers of this and hydrogen ions.

pH

The measure of the amount of hydrogen ions in a solution.

Alkaline

Having a pH greater than 7.0 (eg. pH=8.9)

Amphoteric

Having properties of an acid and a base (eg. buffers such as HCO3 -)

Organic

Containing carbon and hydrogen (eg. CH3)

Inorganic

Molecules that do not have a carbon-based structure (eg. NaCl)

Methane

Hydrocarbon, CH4

Ethane

Hydrocarbon, C2H6

Dehydration synthesis/Condensation

Type of metabolic reaction involving the combination of small molecules together to make a larger product.

Hydrolysis

Type of metabolic reaction involving the breaking down of larger molecules into their components with the addition of water.

Carbohydrate

Include sugars (glucose, ribose, maltose, etc.) and polymers (starch, cellulose, glycogen, etc.). Have the empirical formula: CH2O

Lipid

Class of biochemicals that is immiscible in water. Sometimes called macromolecules, but limited to the size of polymers they can form. (eg. fats, oils, steroids)

Empirical formula

Simplest version of a molecular formula (eg. Carbohydrates is CH2O)

Sugar

General term for a simple carbohydrate, either a monosaccharide or disaccharide

Glucose

C6H12O6, simple sugar produced by photosynthesis in plants

Monosaccharide

Simple sugar such as glucose, fructose, and ribose

Fructose

“Fruit sugar”. Naturally occurring sugar in fruit that is metabolized for energy by carbohydrate metabolism

Galactose

Monosaccharide component of lactose

Isomer

Different arrangement of the same number and kind of atoms forming substances with different chemical properties (eg. fructose and glucose are isomers since they are both C6H12O6)

Deoxyribose

C5H10O4

Ribose

C5H10O5

Maltose

Disaccharide that is made by the combining of two glucose molecules

Disaccharide

Double sugar. The dehydration synthesis of two monosaccharides produces this

Sucrose

Combination of glucose and fructose, table sugar.

Lactose

The combination of glucose and galactose, milk sugar.

Polysaccharide

Large molecules containing many monosaccharides

3 main types of polysaccharides

Starch, glycogen, cellulose

Starch

Polymer of glucose that is made by plant tissues as a way to store glucose

Glycogen

Branching polymer of glucose molecules, a polysaccharide storage form of glucose in the liver

Cellulose

Polysaccharide that forms supportive cell walls. Humans cannot digest it and use it as a dietary fibre

Non-polar

Molecular bonds where the sharing of electrons is relatively equal, not creating any polarity

Hydrophobic

Will not mix with water, as opposed to hydrophilic (eg. lipids)

Fatty acids

Long chain carboxylic acids, can be saturated or unsaturated

Steroids

Complex lipid that have a characteristic 4-ring structure (eg. cholesterol, sex hormones)

Carboxylic acid

Hydrocarbon with a carboxyl group

Saturated

Long chain carboxylic acids that do not contain any double bonds, and are therefore saturated with hydrogen atoms

Unsaturated

Having one or more double bonds in its carbon chain, and is therefore not saturated with hydrogen

Glycerol

Three-carbon alcohol that combines with long chain fatty acids to produce neutral fats

Triglyceride

Neutral fat consisting of glycerol combined with three fatty acids

Phospholipid

Neutral fat consisting of glycerol with two fatty acids bonded to it

Hydrophilic

Will mix with water, as opposed to hydrophobic

Cholesterol

A type of steroid usually produced by the liver and distributed about the body by the circulatory system