Microbiology chapter 2 The molecules of life

Atoms are…

Basic units of matter

Neutrons

Uncharged found in nucleus

Protons

Positively charged found in nucleus

Electrons

Negatively charged, Found in shells around nucleus

Atomic number is

Number of protons

Atomic mass

Number of protons and neutrons

Isotopes

Atoms with the same atomic number but different mass numbers

How many different types of bonds can form and what are they?

3 Covanlent, Ionic, Hydrogenn

Ionic bonds

Formed by atoms gaining or losing electrons, strongest of bonds

Covalent bonds

Formed when atoms share electrons, a weaker bond

Hydrogen bonds

Atoms bond with a hydrogen generally a weak bond

Adenosine triphosphate

(ATP) Energy supplier of the cell

4 major classes of Macromolecules

Proteins

Carbohydrates

Nucleic acids

Lipids

Roles of proteins

• Catalysis

• transport

• movement

• cellular framework

• cellular response

• gene expression

Which macromolecule is more than half of a cells dry weight

Proteins

Building blocks of proteins are —--

Amino acids

How many amino acids are found in proteins

20

what holds amino acids together

Peptide bonds

What determines a protein’s shape

Amino acid sequence

Protein structure levels….

Primary - chain of amino acids

Secondary structure - helix or sheet

Tertiary - 3D

Quaternary - complete protein

What happens when a protein denatures

It becomes inactive; loses its shape

What causes protein denaturation

High temperature, extreme pH and harsh solvents

Carbohydrates are a source of what?

Energy and carbon source

What is the general formula or ratio of a carbohydrate?

General formula (CH2O)n

Ratio 1:2:1 Carbon:Hydrogen:Oxygen

What is a monosaccharide and examples

A single unit carbohydrate

Eg: Glucose, Fructose, Mannose, Galactose

What is a Disaccharide?

Two monosaccharides joined by a covalent bond

Sucrose

Glucose + Fructose

Lactose

Glucose + Galactose

Maltose

Glucose + Glucose

Polysaccharides and examples

Chains of monosaccharides

• Often made from glucose

Eg:

• Cellulose

• Starch

• Glycogen

• Dextran

Nucleic acid

Carries genetic information in sequence of nucleotides

Types - DNA or RNA

DNA

Deoxyribonucleic acid

RNA

Ribonucleic acid

Two classes of nuceotides

Purines or Pyrmidines

Purines

Adenine (A), Guanine (G)

Pyrimidines

Cytosine ( C ), Thymine (T), Uracil (U only in RNA)

A bonds to ?

T: A bonds to T

C bonds to ?

G: C bonds to G