Topic 2- molecular Biology

Why is water polar?

Due to unequal electron sharing between oxygen and hydrogen

Why is water a good solvent?

Because polarity allows dissolution of ionic substances

Why is water cohesive?

Hydrogen bonding between molecules

Why is water a good coolant?

Because of a high specific heat capacity

What are the examples of monosaccharides?

Glucose, fructose, and galactose

What are the examples of disaccharides?

Sucrose, lactose, and maltose

What are the examples of polysaccharides?

Starch, glycogen, and cellulose

What is the function of starch?

Energy storage in plants

What is the function of glycogen?

Energy storage in animals

What is the function of cellulose?

Structural support in plant cell walls

What are lipids made from?

Glycerol and three fatty acids

What’s the difference between saturated versus unsaturated fatty acids?

Saturated: no double bonds, solid

Unsaturated: double bonds, liquid

What is the function of lipids?

• Long-term energy storage

• Insulation

• Membrane structure

• Hormones

Why are lipids good for energy storage?

• High energy per gram

• Hydrophobic (so contain no water weight)

What are proteins made from?

Amino acids

What is the structure of an amino acid?

• amino group

• Carboxyl group

• Hydrogen

• R group

• Central carbon

What bonds form between amino acids?

Peptide bonds

What is the primary structure?

The sequence of amino acids

What are the secondary structures?

An alpha helix or a beta pleated sheet

What are tertiary structures?

A 3-D folding from our group interactions

What are Quaternary structures?

Multiple polypeptide’s joined together

What are the functions of proteins?

• Enzymes

• Structure

• Transport

• Hormones

• Immunity

What are enzymes?

Biological catalysts made of proteins

What is an enzyme active site?

A region where a substrate binds

What is the lock and key model?

Where substrates fit exactly into the active site they are made for

What is the induced fit model?

Where an active site changes shape to fit the substrate

What is denaturation?

Change in enzyme shape resulting in a loss of function

What factors affect enzyme activity?

• temperature

• pH

• Substrate concentration

• Enzyme concentration

Why does temperature increase enzyme activity?

The higher the temperature, the more collisions between particles

Why does too high a temperature reduce enzyme activity?

Because it results in denaturation

What is a competitive inhibitor?

Substrates that compete for an active site

What is a non-competitive inhibitor?

A substrate that will bind elsewhere or changes she

What does DNA stand for?

Deoxyribonucleic acid

What does DNA nucleotides contain?

• Phosphate

• Deoxyribose sugar

• And amino acid base

What are the DNA bases?

Adenine, Thymine, Cytosine, and Guanine

What are the DNA base pairings?

Adenine-thymine

Cytosine-guanine

What are the bonds between the DNA bases?

Hydrogen bonds

What is the shape of DNA?

A double helix structure

DNA replication is….

Semi conservative

What is the function of helicase?

It unwinds or unzips the DNA’s double helix structure

What is the leading strand?

The continuous synthesis

What is the lagging strand?

The strand made from Okazaki fragments

What is the role of DNA Ligase?

It joins the fragments together

What is transcription?

Where DNA is transcribed into messenger RNA (mRNA)

Where does transcription occur?

In the nucleus

What are the RNA bases?

Adenine, uracil, cytosine, guanine

What’s the difference between RNA and DNA?

RNA:

• Single stranded

• Contains uracil

• And ribose sugar

DNA:

• Double helix structure

• Contains thymine

• And deoxyribose sugar

What is translation?

The process where mRNA is changed into proteins

Where does translation occur?

In the ribosomes

What is a codon?

Three bases that code or a coding for an amino acid

What is an anticodon?

Where transfer RNA (tRNA) is a complementary sequence

What is an example of a start codon?

AUG (adenine, uracil, guanine)

What are Some examples of stop codons?

UAA (uracil, adenine, adenine), UAG (uracil, adenine, Guanine), UGA (uracil, guanine, adenine)

What’s the difference between ribose and deoxyribose sugars?

Deoxyribose is missing the oxygen at the 2’ carbon