Bio Hon Unit 2 Chemistry of Life (UPDATED 10-17; Still under construction)

atom

Basic unit of matter.

Nucleus

The center of an atom which contains protons and neutrons.

Electron

Negatively charged particle, located outside the atomic nucleus.

Ionic bond

Bond formed by attraction between oppositely charged ions. Occurs when one or more electronss are transferred from one atom to another.

Ion

Atom that has a positive or negative charge.

Covalent bond

Bond formed by sharing electrons.

Molecule

Smallest unit of a compound.

Hydrogen bond

weak attraction between a hydrogen atom and another atom

Monomer

Small unit that can join together with other small units to form polymers.

Polymer

Large compound formed from combinations of many monomers.

Carbohydrate

Compound made up of carbon, hydrogen and oxygen atoms. Major source of energy for the human body.

Monosaccharide

Single sugar molecule (C6H12O6)

Polysaccharide

Large macromolecule formed from several monosaccharides linked together.

Lipid

Macromolecule made mainly form carbon and hydrogen atoms. Includes fats, oils, and waxes.

hydrogen bond

A type of weak chemical bond formed when the slightly positive hydrogen atom in one molecule is attracted to the slightly negative atom in another molecule.

Why is water polar?

has polar covalent bonds; H is partially positive, O is partially negative

polarity of water results in

hydrogen bonding & good solvent of polar molecules

What causes surface tension in water?

strong cohesive forces between water molecules, specifically due to hydrogen bonds

Atoms

The smallest unit of an element that retains all the properties of that element.

Stability of Atoms

An atom is more stable when its outermost energy level is filled.

Electrical Charge

An atom becomes an ion when its number of electrons does not equal its number of protons, resulting in an electrical charge.

Ionic Bond

Some atoms become stable by transferring electrons.

Covalent Bond

Formed when atoms share pairs of electrons in covalent bonds.

Shared Electrons

Shared pairs of electrons fill the outermost energy levels of the bonded atoms.

Water Molecule Properties

The oxygen atom attracts more than its share of electrons.

Hydrogen Bonds

An attraction between a hydrogen atom and an electronegative atom, often oxygen or nitrogen.

Homeostasis

Ability to maintain a stable internal environment despite changing conditions.

High Specific Heat

Water must absorb a relatively large amount of heat energy to increase temperature.

Cohesion

Attraction among molecules of the same substance.

Adhesion

Attraction among molecules of different substances.

Capillary Action

Allowing water to travel upward against gravity.

Macromolecule

These are large molecules, often formed by joining smaller molecules together.

Monomers

Smallest unit of a large molecule (building blocks of things).

Polymers

The large molecule formed by joining monomers.

2 Functions of Carbohydrates

1. Energy source 2. structural.

Disaccharide

2 sugars. Ex. sucrose

Elements of Carbohydrates

C, H and O

Monosaccharides

Simple sugars like glucose, galactose, and fructose.

Glucose

Made during photosynthesis; Main source of energy for plants and animals.

Fructose

Found naturally in fruits; Is the sweetest of monosaccharides.

Galactose

Found in milk; Is usually in association with glucose or fructose.

Disaccharide Definition

Two monosaccharides bonded together.

Sucrose

Made up of glucose + fructose bonded together.

Lactose

Made up of glucose + galactose bonded together.

Storage Polysaccharides

Examples include starch and glycogen.

Examples of Structural Polysaccharides

Examples include cellulose and chitin.

Complex Carbohydrate

A polysaccharide with many monosaccharide units.

Lipid polarity

non-polar (hydrophobic)

Elements of Lipids

C, H, O

Building Block of Lipids

1 glycerol and 3 fatty acids

Saturated Fatty Acids

Fatty acids are 'full' of Hydrogens; all carbon bonds are single. Solid at room temp.

Unsaturated Fatty Acids

At least 1 double bond between carbons. Liquid at room temp.

Trans Fats

Made by humans; takes an unsaturated and makes it act saturated.

Amino Acid

Monomer of protein with an amino group on one end and a carboxyl group on the other end.

# of Amino Acids

20

Essential Amino Acids

Amino acids that the body cannot produce on its own and must be obtained through diet.

Non-Essential Amino Acids

Can be synthesized by the body and do not need to be consumed through food.

Functional Groups of Amino Acids (NOT ON TEST)

An amino group (-NH2), a carboxyl group (-COOH), and a side chain (R group).

Functions of Proteins

-controls rate of reactions
-transport
-structural
-protective

Ribonucleic Acid (RNA)

Single-stranded nucleic acid that contains the sugar ribose.

Deoxyribonucleic Acid (DNA)

Double-stranded nucleic acid that contains the sugar deoxyribose.

Nucleotide

Monomer of nucleic acids

2 forms of nucleic acids

DNA or RNA (can be single or double-stranded; linear or circular)

functions of lipids

- E storage
-waterproofing
-insulation
-cell membranes

functions of nucleic acids

store and transmit information

dehydration synthesis

A chemical reaction in which two molecules are bonded together with the removal of a water molecule.

hydrolysis

A chemical process that splits a molecule by adding water.