Cell Chemistry (Ch 2)

Basic Chemical Reactions

Must be balance

* Ex: 2H2 + O2 → 2H20
* Reactant → Product

Biological Molecules important to cells

1. Protein
2. Carbohydrate
3. Nucleic Acid
4. Lipid (have different structures so are not polymers)

Macromolecules (Polymers)

Very large and composed of monomers

* Protein
* Carbohydrate
* Nucleic Acid

Monomer

* Amino Acid
* Monosaccharide
* Nucleotide

Polymer

* Polypeptide
* Polysaccharide
* Polynucleotide

Polymer Formation

Long molecules made of repeating building blocks called monomers

Dehydration Synthesis

Reaction creates a water molecule.

* Polymer is formed
* Monomer is joined by removal of OH from one monomer and removal of H from other at site of bond formation

Hydrolysis Reaction

Takes in a water molecule

* Polymers are broken apart
* Monomer is released by addition of water adding OH to one monomer and H to the other.

Protein

* Monomer: Amino acid (20 of these)
* Polymer: Polypeptide (peptide bond)
* Enzyme

Amino acid

20 different kinds. The sequence of these is what determine the shape and function of a protein.

Peptide bond

amino acids bonded together by covalent bond.

Denature

proteins that are exposed to harsh conditions (ex: high heat) become nonfunctional. Cannot be undone.

Enzyme

Protein that speeds up chemical reactions.

* Break apart or build molecules.
* Specific to substrate which is determined by shape.
* Name usually ends with -ase

Carbohydrate

Source of chemical energy in living organisms (ATP)

* Important in the structure of some cells.
* Bacterial Cell walls
* Plant cell walls
* Monomer: Monosaccharides (simple sugar)
* Disaccharide: 2 sugars
* Polysaccharides: many sugars (polymer)
* Starch: used to make energy for cells.

Disaccharide

2 sugars

Polysaccharide

Polymer of many sugars

Starch

used to make energy for cells

Nucleic Acid

Store and transfer genetic information.

* Monomer: nucleotide
* DNA
* RNA

DNA (Deoxyribonucleic Acid)

Double helix structure bound by hydrogen bonds

RNA (Ribonucleic Acid)

Single stranded structure

Pentose Sugar

Deoxyribose and Ribose

Purine Base

Adenine (A) and Guanine (G)

Pyrimidine Bases

Thymine (T), Cytosine (C), and Uracil (U)

Lipid

Macromolecule but not a polymer


1. Fat: 3 carbon backbone with fatty acid chains (long chains of carbon) attached.
2. Phospholipid: phosphate head, glycerol backbone, 2 fatty acid tails.
3. Sterols: 4 carbon rings.

Fat

3 carbon backbone with fatty acid chains (long chains of carbon) attached.

* Unsaturated
* Saturated

Phospholipid

phosphate head, glycerol backbone, 2 fatty acid tails.

* Compose cell membrane
* From bilayer in water
* Hydrophilic head and hydrophobic tail

Sterol

4 carbon rings.

* Also known as steroids
* Cholesterol is a component of cell membranes
* Hormones
* Vitamins