Lecture 2

Question 1

What are polymers?

Answer 1

A chain of repeating monomers that are similar but not identical

Question 2

What are proteins? How do you classify them?

Answer 2

Polymers of amino acids that are classified by their R group

Question 3

What is a protein made up of?

Answer 3

The base of a protein is made up of NH3+, C, H and COO-. An R group is attached to this base. The C is a carboxy group and the N is a amino group

Question 4

How do you classify and R group?

Answer 4

An R group can be non-polar, polar uncharged, polar charged acidic and polar charged basic

Question 5

How do you know what to classify an R group?

Answer 5

Non-polar=CH Polar uncharged= -OH or -SH Polar charged acidic=there is negative charge Polar charged basic=there is a positive charge

Question 6

What is the directionality of proteins? Extensibility?

Answer 6

N to C or NH3+ to COO-. Other proteins can be added but N always has to be start and C always has to be end

Question 7

What is 1°?

Answer 7

Primary Structure. It dictates folding and folding dictates functions

Question 8

What is 2°?

Answer 8

Secondary Structure. The a.a fold into a Beta Sheet and/or an Alpha Helix

Question 9

What is 3°?

Answer 9

Tertiary Structure. 3D folding, hydrophobic R groups drive a.a away from water into middle of protein

Question 10

How is 3° maintained?

Answer 10

Covalent bonds- disulfide bridges between 2 cytosine. Ionic Bonds- between oppositely charged a.a. Hydrophobic interactions- between nonpolar a.a. Hydrogen bonds- between polar uncharged a.a

Question 11

What is 4°?

Answer 11

Some proteins form multisubunit complexes that create a functional protein. Held together by same forces as 3

Question 12

What is a Nucleosome?

Answer 12

DNA coiled around histones, this is an example of 4° structure

Question 13

What is DNA? What is its directionality?

Answer 13

A polymer of Nucleotides. Its directionality is 5 to 3

Question 14

What are the 4 nucleotides?

Answer 14

A, G, T, C

Question 15

How do you identify a Nucleotide?

Answer 15

A=purine/double ringed, has no O’s in the base. G=purine/double ringed, has O’s in the base. T=pyrimidine/single ring, 3 functional groups. C=pyrimidine/single ring, does not have 3 functional groups

Question 16

What is a Sugar? What is its function?

Answer 16

Sugars are polymers of mono or disaccharides. They are an energy source, the are essential to cell structure and they assist in cell-cell recognition.

Question 17

What is starch? What is its structure?

Answer 17

Starch is a polysaccharide that is energy storage for plants. It is a polymer of glucose. It contains an alpha 1-4 carbon glyosidic bond. Animals can beak done the alpha bond

Question 18

What is cellulose? What is its structure?

Answer 18

Cellulose is a polymer of glucose and is the cell wall in plants. It contains beta 1-4 carbon glyosidic bonds. Only bacteria can break down beta bonds

Question 19

What is peptidoglycan?

Answer 19

Polymer of NAG and NAM. It is the structural basis for bacteria cell walls. It has directionality of C1-C4

Question 20

What is a glyosidic bond?

Answer 20

A covalent bond between sugars

Question 21

What are the 2 ways to create and destroy polymers?

Answer 21

Synthesis-condensation/dehydration reactions. Breakdown-hydrolysis reaction

Question 22

How does hydrolysis work?

Answer 22

Water is added to a a polymer and splits monomers apart. Energy is released. The reaction is spontaneous but slow.

Question 23

How does Synthesis work?

Answer 23

Add monomers to a growing reaction chain, a covalent bond forms between them. This requires energy and water is a product.

Question 24

What are lipids?

Answer 24

Not a true polymer, they are made mostly of HC. Are hydrophobic and aggregate away from water

Question 25

What is a fatty acid?

Answer 25

Single chains of mostly HC with a COOH end. Then can esterify to a glycerol

Question 26

What is Fat?

Answer 26

Three fatty acid tails esterify with a glycerol and create triglyceride which is animal fat. Function as energy storage and insulation

Question 27

What is the difference between saturated and unsaturated fats?

Answer 27

Saturated fats are linked with all single C bonds, meaning the fatty acids tails are straight. Unsaturated fats are linked with double C bonds, meaning the fatty acids have a kink

Question 28

What are phospholipids?

Answer 28

Phospholipids have a hydrophilic head made of phosphate which is connected to fatty acid tails with glycerol. The fatty acid tails are hydrophobic. The entire phosphide is amphpalic meaning it has a hydrophilic domain and a hydrophobic domain.

Question 29

How do phospholipids form? Do they have covalent bonds?

Answer 29

Phospholipids have no covalent bonds and spontaneously self assemble

Question 30

What is a steroid? What is its structure? What do the do?

Answer 30

A steroid is a class of lipids based on cholesterol. They have a backbone of 4 HC groups and also a small polar functional group. They are hormones.

Question 31

How are amino acids bonded?

Answer 31

A peptide bond between a carboxy and amino group

Question 32

What is the structure of DNA?

Answer 32

A 5 carbon sugar (called a ribose), a nitrogenous base and a phosphate

Question 33

What attaches to each Carbon in DNA?

Answer 33

C1- attaches to base. C2- attaches to nothing/H(but in RNA it attaches to OH. C3- attach to 3' OH which is essential for polymerization. C4- boring. C5- attaches to phosphate