Biomolecules

Question 1

Name the dietary carbohydrates and relevant info

Answer 1

1) Starch
- Food source for plants
- Polysaccharide of GLUCOSE

2) Sucrose
- Found in fruits and vegetables
- Disaccharide of glucose and fructose (think Fruit-close)

3) Dietary fiber
- Comes from plants (Grains, etc.)

4) Lactose
- Sugar from milk, therefore animal origin
- Disaccharide of glucose and galactose (think (ga - lactose)

Question 2

Describe Lactose Intolerance

Answer 2

1) Genetic deficiency of lactase enzyme, which breaks down milk
- Age-dependent decrease in enzyme (i.e. gets worse with age)

2) Results in gas, bloating and belly pain within 2 hours of consuming lactose.

Question 3

What does catabolic vs anabolic mean

Answer 3

Catabolic - breakdown

Anabolic - buildup

Question 4

Describe the good, the bad and the ugly of blood glucose levels and the impact

Answer 4

Hypoglycemia ——- <60 mg/dL (hunger, sweating, trembling)
——- <40mg/dL (coma, brain damage, death)

Normal —————- 70-100mg/dL (fasting), 100-140mg/dL (fed)

Diabetes mellitus — > 126mg/dL (fasted), >199mg/dL (fed)

Question 5

Explain Glycolysis (as well as a certain pathology marker…)

Answer 5

1) The metabolism of glucose (how most cells generate energy)
2) Energy formed = 2 net ATP
3) 6 Cs of glucose are broken down to 2x 3Cs of pyruvate

Aerobic conditions = suppressed glycolysis (EXCEPT CANCER)
-Which is why cancer is a good marker (done with PET scans)

Question 6

What is the formula for glucose?

Answer 6

C6 H12 O6

Question 7

monosaccharides

Answer 7

Simplest carbohydrate form
Provide short-term energy

1) Glucose
2) Fructose
3) Galactose
4) Ribose

Mnemonic — Good Roads Find God

Question 8

Disaccharides (and alpha, beta linkages)

Answer 8

Comprised of two monosaccharides

1) Maltose (alpha 1->4 bond)
2) Lactose (beta 1-4 bond
3) Sucrose (alpha 1, beta 2 bond)

Mnemonic - Many Liquid Sugars

Question 9

Oligosaccharides

Answer 9

• Made of 3 to 10 monosaccharides
• Covalently attaches to membrane proteins and lipids

1) Glycolipids
2) Glycoproteins

Question 10

Polysaccharides (types and purpose)

Answer 10

• More than 10 monosaccharides
• Important for:
  
  • Carbohydrate storage
  • Structural/mechanical support (especially cellulose)

1) Glycogen ———- Chains are a(1-4), Branches are a(1-6)
2) Starch—————Chains a(1-4), branches a(1-6) (water soluble!)
3) Cellulose————Chains b(1-4)

Question 11

Name the Modified Monosaccharides

Answer 11

1) Deoxyaldose - in DNA (that’s why deoxyribonu…)
2) Acylated amino sugars - part of Glycolipids and proteins, thus important for cell signaling
3) Acidic sugars - Located in 1) Cell membrane and 2) the extracellular matrix

4) Food additives —— Sugar Alcohols (Mannitol, sorbitol, xylitol,etc.) -important in diabetes because SORBITOL could lead to peripheral neuropathy
- Galacitol could cause cataracts

Question 12

Describe a Glycosidic Bond and the alpha and beta differences

Answer 12

A covalent bond, formed during a condensation run, between a carbohydrate and another group, usually a carbohydrate

Alpha Linkage - glycosidic bond is below the plane of the sugar rings

Beta Linkage - glycosidic bond is above plane as the sugar rings
TIP! - aBove the sugar rings, its Beta (not the uppercase B)

Question 13

Relevance of sugar alcohols (sweetness) in diabetes??

Answer 13

1) Glucose in the body can be converted into Sorbitol
2) Sorbitol draws water into wherever it is, leading to the destruction of the:
Lens -> cataracts
Pericytes ->retinopathy
Schwann cells -> peripheral neuropathy

Question 14

Facts about Sugar alcohols?

Answer 14

1) Fewer calories per gram than sugar
2) Not as readily absorbed
3) No tooth decay

Question 15

Name two types of starch and their alpha, beta linkages

Answer 15

1) Amylose (found this form 25% of the time) — alpha(1-4)

2) Amylopectin (found this form 75% of time —- a(1-4) and a(1-6)

Question 16

Four types of Dietary Lipids

Answer 16

1) Fatty Acids—————-long, uncbranced hydrocarbon chains
2) Triacylglycerol
3) Cholesterol esters
4) Phospholipids

Question 17

Structure of ester, carboxylic acid and glycerol

Answer 17

??

Question 18

Cholesterol esters

Answer 18

Fatty acid esterified to a cholesterol

Fatty acid + cholesterol

Question 19

Triacylglycerol

Answer 19

3 Fatty Acids + glycerol backbone

Question 20

Membrane Lipids

Answer 20

1) Glycerophospholipid—-fatty acid + glycerol + phosphate
2) Sphingophospholipid—fatty acid + amino alcohol or sugar alcohol
3) Glycolipid——————sugar + fatty acid

Question 21

Lipid-soluble Vitamins (And IPP unit number)

Answer 21

Vitamin A—leafy vegetables, carrots (def.= night blindness) (4)
Vitamin D—sunlight, fortified milk (def.= no bone mineralization) (6)
Vitamin E—veg. Oils, leafy vegetables (def.= muscular dystrophy)(4)
Vitamin K—leafy vegetables (def. poor blood coagulation)(4)

All are 4 IPP units except Vitamin D

Question 22

Omega 3 & Omega 6 fatty acids

Answer 22

The “3” and the “6” indicate the location of the terminal double-bond. Count # of carbons from end to double bond.

Ex. Linolenic acid is w-3

Ex. Linoleic & Arachidonic acids are w-6

Question 23

Isoprenoids (structural features)

Answer 23

1) Lipids made from ACETYL CoA from isopentenyl pyrophosphate (IPP)
2) Organic compounds from 2 or more hydrocarbon units, consisting of 5-carbon atoms
3) IPP condensation = creation of isoprenoid (steroids, lipid soluble vitamins, etc.)

Most Common & important——-> Cholesterol

Question 24

Cholesterol (& associated pathology)

Answer 24

1) Most common steroid
2) Important as:
-Precursor to other steroids, bile and Vitamin D
-In membranes
Pathology: Gallstones
1) Salt in the gallbladder keep cholesterol in solution (aqueous state)
2) Too much cholesterol/too little salt results in cholesterol precipitating into GALLSTONES
3) Ongoing issues with metabolism can lead to 1) malabsorption (decreased ability to absorb food) and 2) fat-soluble vitamin deficiencies)
4) This is because bile is needed to emulsify fats - remedy is Chenodeoxycholic, which can dissolve gallstones.

Question 25

Structural features of Amino Acids

Answer 25

Central C with four groups:

1) alpha-carboxylic group
2) alpha-amino group
3) hydrogen group
4) Side chain (R-group)

Question 26

Essential Amino Acids (10 of them)

Answer 26

*Needs from diet
Mnemonic (PVT TIM HALL)

1) Phenylalanine
2) Valine
3) Tryptophan
4) Threonine
5) Isoleucine
6) Methionine
7) Histidine
8) Arginine
9) Lysine
10) Leucine

Question 27

Amino Acids that are Glucogenic and Ketogenic

Answer 27

Think PITTT

1) Phenylalanine
2) Isoleucine
3) Tryptophan
4) Tyrosine
5) Threonine

Question 28

Basic Amino Acids

Answer 28

Key: does it have nitrogen/ammonia group/

1) Arginine
2) Lysine
3) Histidine

Question 29

Non-Polar AA

Answer 29

Think GLAM VIP - so glamorous they must be VIPs

Glycine
Leucine
Alanine
Methionine
Valine
Isoleucine
Proline

Also, polar AA have an O or S, with or without a hydrogen attached