Pre-enzyme stuff: macromolecules, functional groups, lipids, proteins (2)

Question 1

List two macromolecules and two micronutrients.

Answer 1

Macromolecules:
- Carbohydrates |CHO|
- Lipids |CHO|
- Proteins |CHON|
- Nucleic acids (DNA/RNA) |CHONP|

Micronutrients:
- Vitamins
- Minerals (e.g. calcium)

Question 2

Define a catabolic and anabolic reaction.

Answer 2

Catabolic: Breaking down complex molecules to simpler compounds. Usually there is a net energy release. (Example: cellular respiration)

Anabolic: Synthesizing a complex molecule from simpler compounds. Usually it requires an energy input. (Example: photosynthesis, DNA replication, protein synthesis)

Question 3

Define metabolism.

Answer 3

An organism’s metabolism is the net sum of all of its anabolic and/or catabolic reactions

Question 4

Define dehydration synthesis (or condensation reactions) and hydrolysis reactions.

Answer 4

Dehydration synthesis: a reaction where two molecules are covalently bonded to each other through loss of water.

Hydrolysis reactions: A reaction where a covalent bond between two molecules is broken through the addition of water.

Remember that these two are opposites :)

Question 5

Wild carrrrrd! Look at formation of glycosidic bond, hydrolysis of sucrose, condensation reaction between glycerol and fatty acids, ester bonds, and condensation reaction between amino acids.

https://docs.google.com/presentation/d/1kOxX3Q6TbS_8BlgKBxXWfiY0MDuQH-cE_WnjlbZ9FlY/edit#slide=id.p10

Question 6

Define a macromolecule.

Answer 6

A large molecular weight compound formed by polymerization of small molecules.

Polymerization: process of reacting monomer molecules together in a chemical reaction to form polymer chains or three-dimensional networks.

Question 7

What is the chemical formula for glucose?

Answer 7

(C6)(H12)(O6)

Question 8

What are the 3 monosaccharides?

Answer 8

• Fructose
• Glucose
• Galactose

(Monosaccharides are the basic unit of carbohydrates)

Question 9

Wild carrrrrd! Make sure you can draw alpha and beta glucose. Also, what’s the difference between the two glucose types?

https://docs.google.com/presentation/d/1Cn0ObVXQASslehHyFB1k6ytWDX22bHoYAOXSMloQOhs/edit#slide=id.g168f320647e_0_0

Answer 9

The hydroxide (OH) in alpha glucose is below the plane of the ring whereas in the beta glucose it is above the plane.

Question 10

What are the three disaccharides? (Let Me See) Try and state what each are composed of.

Answer 10

• Lactose = galactose + glucose
• Maltose = glucose + glucose
• Sucrose = fructose + glucose

Question 11

What are polysaccharides? Give some examples.

Answer 11

They’re “complex carbohydrates”, made of long chains of 3 or more monosaccharides.

Energy Storage:
- Starch (plants)
- Glycogen (animals)

Structural use:
- Cellulose (plants)
- Chitin (fungi, arthropods)

Question 12

Describe the sources, subunits, bonds, and branch status of:

• Cellulose
• The two starches
• Glycogen

Answer 12

Source:
Cellulose - plants
Amylose - plants
Amylopectin - plants
Glycogen - animals

Subunits:
Cellulose - beta glucose
Amylose - alpha glucose
Amylopectin - alpha glucose
Glycogen - alpha glucose

Bonds:
Cellulose - 1-4
Amylose - 1-4
Amylopectin - 1-4 and 1-6
Glycogen - 1-4 and 1-6

Branches?:
Cellulose - No
Amylose - No
Amylopectin - Yes (per 20 subunits)
Glycogen - Yes (per 10 subunits)

Question 13

What are the two main functions of carbohydrates?

Answer 13

> Provide energy storage for living organisms:
- Short Term: sugar (glucose, maltose, lactose)
- Long Term: starch/glycogen
Provide the building block for the structure of organisms
- Cellulose (plants)
- Chitin (fungi)
- Sugars (mono/di)

Question 14

What is the difference between fats and oils?

Answer 14

Fats are solid at room temperature
Oils are liquid at room temperature

Question 15

State the functions of lipids (SHIPS), as well as the two components that make them up.

Answer 15

S - Storage/Source of energy.
H - Hormonal roles.
I - Insulation.
P - Protection.
S - Structural components.

1 glycerol molecule and 3 fatty acid molecules.

Question 16

What are phospholipids?

Answer 16

A variation of a triglyceride used in cell membranes:

one fatty acid chain is replaced by a phosphate group (PO4).
PO4 is negatively charged and makes a polar “head” on the molecule

Question 17

What are the different types of lipids?

Answer 17

Lipids can be classified based on the level of hydration of the carbon atoms in the fatty acid chain
Saturated:
- All carbons have max number of hydrogen atoms

Mono-unsaturated:
- Only one double bond between carbons
- Carbons not fully saturated

Polyunsaturated:
- More that one double bond
- Several carbons not fully saturated

Question 18

Explain how saturated and unsaturated fats differ.

Answer 18

Saturated fats:
- Linear
- Tightly packed, so solid at room temp
- Single bond

Unsaturated fats:
- Kinked
- Loosely packed, so liquid at room temp
- Double bond

Question 19

Describe the London Force.

Answer 19

• The weakest intermolecular force.
• A temporary attractive force due to electrons in two adjacent atoms occupying positions that make the atoms form temporary dipoles.
• Sometimes called an dipole-induced dipole attraction.
• The attractive forces that cause nonpolar substances to condense to liquids and to freeze into solids when the temperature is lowered sufficiently.

Question 20

Explain the association between hydrogenation and trans fats.

Answer 20

Trans fatty acids do not commonly occur in nature and are typically produced by called hydrogenation. Some plant oils are artificially “hydrogenated” to make them more solid.

Question 21

What are the five most prominent differences between cis and trans fats (Homophobic Animals Sleep Pretty Badly)? Why do we use trans fats?

Answer 21

• Hydrogen on same side vs hydrogen on opposite side (HYDROGEN)
• Most common natural bond vs occurs naturally in small amounts in red meat / dairy (ABUNDANCE)
• Causes a kink (bend) in fatty acid vs results in linear fatty acid (STRUCTURE)
• Loosely packed vs more tightly packed (PACKING)
• Beneficial for the body and adds good cholesterol vs not effectively broken down by the body (BREAKDOWN)

Trans fats have an appealing taste, last longer, and are more stable at higher temperatures.

Question 22

What are the four major macromolecule tests, what do they identify, and what change is visible in each?

Answer 22

Benedict’s Test: Identifies presence of simple sugars like glucose. Solution changes from blue to reddish brown.
Iodine Test: Identifies presence of starch. Iodine changes from brown to bluish-black.
Biuret’s Test: Identifies presence of peptide bonds. Solution changes from blue to pale violet.
Spot Test: Identifies presence of lipids. Brown paper becomes translucent.

Question 23

What does the presence of glucose and protein respectively in your urine indicate?

Answer 23

Glucose: You have too much glucose in the blood and some is filtered out through your urine. You may have diabetes.
Protein: Protein may be leaking out from kidney filters into the urine. This could be a sign that the kidneys are damaged.

Question 24

What does the structure of proteins consist of? What elements make them up (CHONS)?

Answer 24

They consist of long chains of amino acids (monomers).

• Carbon
• Hydrogen
• Oxygen
• Nitrogen
• Sulfur (some side groups)

Question 25

How do all amino acids differ? Define nonessential vs essential amino acids?

Answer 25

They all differ in the type of side group (residual group “R”) attached to the basic structure:

The 12 nonessential amino acids can be made by your cells.
The other 9 essential acids have to obtained from your food

Question 26

Describe the functions of proteins (STD ME)

Answer 26

• Structural
  Major structural components of cells and tissues (muscle)
• Transport
  Form channels that help transport molecules
• Defense
  Form the “antibodies” of your immune system
• Messengers
  Make protein hormones (eg. insulin)
  across cell membranes
• Enzymes
  Act as catalysts for ALL biochemical reactions

Question 27

What is the rule for the amount of genes that can code for a polypeptide, and what are the exceptions to the rule? (

Answer 27

One gene must code for one polypeptide.

Exceptions:
1. Genes may be alternatively spliced to generate multiple polypeptide variants (Splicing)
2. Genes encoding tRNA sequences are transcribed but never translated (tRNA Scribed Never Slated)
3. Genes may be mutated and consequently produce an alternative polypeptide sequence (Mutation)

Question 28

What determines the function of a protein?

Answer 28

Its shape!

(They have a large variety of shapes because each AA chain is folded into a unique 3D shape, which is determined by the bonding and the forces acting between respective R groups of AAs along the chain)

Question 29

Describe the four types of amino acid structures and their bonds.

Answer 29

Primary structure: AA sequence of polypeptide chain. Held together by peptide bonds.
Secondary structure: Arrangement of polypeptide’s main chain atoms. Held together by hydrogen bonds.
Tertiary structure: 3D structure of entire polypeptide chain. Maintained by disulfide bonds, hydrophobic interactions, hydrogen bonds, ionic interactions, and van der Waals forces. Includes alpha helixes and pleated sheets.
Quaternary structure: Proteins made up of multiple polypeptide chains (subunits).

Question 30

Compare and contrast fibrous and globular proteins (SPADES). Explain the reasoning behind each protein’s solubility or lack thereof.

Answer 30

SHAPE
- Fibrous: long and narrow
- Globular: spherical
PURPOSE
- Fibrous: structural
- Globular: functional
AMINO ACID SEQUENCE
- Fibrous: repetitive
- Globular: irregular
DURABILITY
- Fibrous: Less sensitive to changes in pH, temperature, etc
- Globular: More sensitive to changes in pH, temperature, etc
EXAMPLES
- Fibrous: collagen, myosin, fibrin, keratin, actin, elastin
- Globular: hemoglobin, myoglobin, enzymes, insulin, immunoglobin
SOLUBILITY
- Fibrous: Generally insoluble in water because of hydrophobic R-groups sticking out of the molecule
- Globular: Generally soluble in water–hydrophobic amino acids are bound into interior while hydrophobic amino acids bound outwards

Question 31

Give one example of a fibrous protein, and state what the protein does.

Answer 31

Keratin: helps form hair, nails and skin’s outer layer (epidermis). supports skin, heals wounds, keeps nails and hair healthy

Collagen: responsible for healthy joints and skin elasticity, or stretchiness. Located in tendons, skin, bones, and teeth.

Question 32

Give one example of a globular protein, and state what the protein does.

Answer 32

Hemoglobin: contains iron, which allows it to pick up oxygen from the air we breathe and deliver it everywhere in the body. It’s found in the red blood cells.

Myoglobin: An oxygen binding protein found in skeletal muscle tissue. It provides extra oxygen so the muscles can remain in activity when other available oxygen is expended.

Question 33

Describe the four bonds involved in protein folding (triple Hi)

Answer 33

• Hydrophobic Interactions: Amino acids orient toward center to avoid water
• Hydrophilic Interactions: Amino acids orient towards water
• Hydrogen bonds: Hydrogen bonding with the electronegative oxygen
• Ionic bonds: Charged R groups bond together