Chapter 2: How cells function

*Notes*

Section 2.1:Chemical reactions take place inside cells

1. All cells are made of the same elements.

A. Elements and matter

i. Matter: anything that has mass and takes up space

i. All living and non-living things can be broken down into elements.

ii. Element: substance that cannot be broken down by physical or chemical means.

iii. Each element has it’s own set of properties

Ex: Oxygen is colorless, odorless, and is a gas.

B. Elements in the body

i. Oxygen, carbon, hydrogen, nitrogen, calcium, phosphorus, 19 others.

ii. Can be found as pure element or as a compound.

Compound: atoms of two or more elements joined together by chemical bonds.

Ex: H2O

C. Atoms

i. Atom: smallest unit of an element that still retains the properties of that element.

ii. Chemical reactions: bonds between atoms are broken or formed to make different molecules in the body. (this is necessary for us to live!)

iii. Bonds:

broken bonds = release energy

formed bonds = store energy

2. Large molecules support cell function (Also known as Macromolecules)

A. Carbohydrates

i. Purpose: give us energy!

ii. Make up: carbon, hydrogen, and oxygen

iii. Types:

a. Simple- sugars such as glucose, fructose, galactose

b. Complex- starches, glycogen, cellulose (fiber)

B. Lipids (fats, oils, waxes)

i. Purpose: store energy, insulation, protection

ii. Make up: carbon, oxygen, and hydrogen arranged in a glycerol with 3 fatty acid tails

iii. Types:

a. Saturated- solid fat, bad for you, comes from animals

b. Unsaturated- liquid, better for you, comes from vegetables

iv. HydroPHOBIC- do not dissolve in water

C. Proteins

i. Purpose: growth and repair, enzymes, transport

ii. Make up: carbon, hydrogen, oxygen, nitrogen, sometimes sulfur

iii. Subunits: amino acids

a. job of protein is determined by the order of the amino acids.

b. Body makes some, you must eat food to get the others.

D. Nucleic Acids

i. Purpose: holds genetic information

ii. Make up: carbon, oxygen, hydrogen, nitrogen, phosphorus

iii. Subunits: nucleotides

iv. Types:

a. DNA- deoxyribonucleic acid (the blueprints for our cells)

b. RNA- ribonucleic acid (helps take the blueprints and make protein)

E. Water

i. Purpose: chemical reactions take place in water

ii. Known as the “universal solvent”, dissolves things

ii. Make up: 2 hydrogen 1 oxygen

iii. Makes up 70% of your body mass

iv. Water cannot dissolve lipids, our membranes are made up of lipids.

Why is this important?