Biochemistry

Question 1

What does molecular biology explain

Answer 1

living processes in terms of chemical substances involved

Question 2

how many bonds does carbon form and its impact

Answer 2

carbon atoms can form 4 bonds allowing diversity of compounds to exist

Question 3

Name 4 carbon compounds life is based on

Answer 3

Lipids, proteins, nucleic acids, carbohydrates

Question 4

what is metabolism?

Answer 4

web of all the enzymes catalyzed reactions in a cell or organism

Question 5

what is anabolism?

Answer 5

synthesis of complex molecules from simpler molecules, including formation of macromolecules from monomers by condensation reactions (eg: protein synthesis)

Question 6

what is catabolism?

Answer 6

breakdown of complex molecules into simpler molecules including hydrolysis of macromolecules into monomers (eg: digestion)

Question 7

what is urea?

Answer 7

example of complex molecule that is produced by living organisms but can be artificially synthesized (the first)

Question 8

differentiate between carbohydrate, protein, and lipid in terms of structure

Answer 8

• Carbs: chains of hexagons and polygons (2:1 hydro:carbon)
• protein: globular or fibrous, variety of R groups
• lipid: long strands, saturated, trans-unsaturated, or cis- unsaturated

Question 9

what are the structural properties of water

Answer 9

• water molecules are polar
• hydrogen bonds form between them (hydrogen to oxygen)
• Negative oxygen molecule with two branching positive hydrogen molecules

Question 10

what properties of water can be explained by bonding and dipolarity?

Answer 10

Adhesive, cohesive, thermal, solvent, high surface tension, high boiling point, low density when frozen, high latent heat of vaporization

Question 11

how do properties of water compare to methane?

Answer 11

• similar size (but 4 branches of H off of O2)
• water is polar, methane non-polar
• water has “higher” properties like density, molar mass, boiling points etc

Question 12

how is water used as a coolant in sweat?

Answer 12

• prevents overheating
• high latent head of vaporization allows us to get rid of heat when sweat evaporates
• lots of energy needed to evaporate, therefore energy drawn from body
• humans transfer heat efficiently vs dogs + birds
• plants use transpiration

Question 13

how does water help transport glucose, oxygen, amino acids, cholesterol, fats, and sodium chloride in blood?

Answer 13

• blood plasma within blood made with water
• sodium chloride dissolves freely
• some amino acids dissolve, some are transported
• glucose is polar so dissolves freely
• oxygen non-polar, not good at dissolving in warm temps, thus needs hemoglobin
• fats are non-polar + insoluble: lipoproteins (phospholipids) carry the fat and cholesterol is spheres, keeps them inside

Question 14

how do monosaccharide monomers link together?

Answer 14

• they are linked together by condensation reaction (release of H2O) to form disaccharides and polysaccharides

Question 15

list 3 examples each of monosaccharides, disaccharides, and polysaccharides

Answer 15

Monosaccharides:
- glucose
- galactose
- fructose
- ribose

Disaccharides
- sucrose (glu + fru)
- maltose (glu + glu)
- lactose (glu + gal)

Polysaccharides
- starch
- cellulose
- glycogen

Question 16

list the functions of 3 polysaccharides

Answer 16

• Starch: sugars, stored in plants temporarily to prevent osmosis
• cellulose: used for structure in plant cell wall
• glycogen: made by animals and some fungi as sugar storage, humans store in muscle and liver (overflow)

Question 17

what are the 3 kinds of fatty acids?

Answer 17

saturated, monounsaturated, or polyunsaturated

Question 18

what are the 2 types of unsaturated fatty acids?

Answer 18

cis and trans isomers

Question 19

how are triglycerides formed?

Answer 19

formed by condensation from 3 fatty acids and 1 glycerol

Question 20

describe the structure and function of cellulose in plants

Answer 20

• structure: open straight links
• function: structure in cell wall

Question 21

structure + function of starch in plants

Answer 21

• structure: alpha glucose all pointing same way, form either helical shape (amylose) or branched shape (amylopectin)
• function: stored temporarily to prevent osmosis

Question 22

structure + function of glycogen in humans

Answer 22

• structure: branched like starch, more branches aka more compact
• function: sugar storage in muscles + liver

Question 23

what is some scientific evidence of health risks of trans-fats and sat-fats?

Answer 23

• sat-fats are naturally occurring, trans-fats created artificially
• increased risk of CHD with intake of sat-fats and trans-fats, although some populations disprove
• coronary arteries become partially blocked by fat leading to blood clots and heart attack

Question 24

compare the energy storage of lipids vs carbohydrates

Answer 24

• lipids can store up to 2x more energy/gram than carbs
• carbs require water, hence fats 6x more efficient in amount of energy
• carbs can be accessed more quickly
• lipids more suitable for long term storage

Question 25

what is the evidence and methods used to obtain evidence for health claims about lipids?

Answer 25

- evidence: positive correlation between amount of trans-fats + sat-fats consumed are rates of CHD - methods of collecting evidence: research programs into sat-fat correlation, tho not all populations agree with trend (Maasai people of Kenya) - people who died of CHD had higher concentration of trans-fats in fat deposits

Question 26

how do cellulose, starch, and glycogen compare with molecular visualization?

Answer 26

- cellulose: 3 layers of hydrogen, carbon, oxygen structures, middle with more (like a sandwich, all beta glucose, not digestible, 1-4 bonds) - glycogen: tubular structure with branches - starch amylose: tube spiraled like DNA (1-4 alpha glucose bonds) amylopectin: non-spiral in crooked form (like zig zag, 1-4 and 1-6 bonds)

Question 27

how do you calculate BMI and use nomograms?

Answer 27

- BMI = weight (lb) / height - can also use table called nomogram

Question 28

how do amino acids link and what do they form?

Answer 28

amino acids are linked by condensation to form polypeptides

Question 29

what do proteins consist of?

Answer 29

may consist of simple polypeptides or more than one polypeptide linked

Question 30

what determines the 3D conformation of a protein?

Answer 30

the amino acid sequence

Question 31

what is the connection between proteins and living organisms?

Answer 31

living organisms synthesize many different proteins with a wide variety of functions

Question 32

identify and describe (+ structure) 3 different proteins essential to humans

Answer 32

- insulin: hormone that signals to cells in body to absorb glucose and reduce blood glucose concentration. Transported by blood, recepted in cell membrane (globular chains) - collagen: rope like structure, most abundant protein in body. Forms mesh of fibers in skin and blood vessels to prevent tearing. - rhodopsin: membrane protein of rod cells in retina of eye. Allows for the retina molecule to change shape upon absorbing light photons, sending nerve impulses to the brain. (globular rope)

Question 33

what are the nucleic acids of DNA and RNA?

Answer 33

polymers of nucleotides

Question 34

how does DNA differ from RNA?

Answer 34

differs by the number of strands normally present, the base composition, and type of pentose

Question 35

What is the structure of DNA?

Answer 35

a double helix made of 2 antiparallel strands of nucleotides linked together by hydrogen boding between complementary bases

Question 36

what are the names of the nitrogenous bases and which are complementary?

Answer 36

- bases in DNA: cytosine (C), adenine (A), guanine (G), thymine (T) - bases unique to RNA: uracil (U) - complementary pairs: adenine + thymine (A+T), cytosine and guanine (C+G)

Question 37

which bases are purine vs pyrimidine?

Answer 37

- purine: adenine and guanine (2 rings) - pyrimidine: cytosine and thymine (1 ring)

Question 38

describe Crick and Watson's discovery of the double helix?

Answer 38

- Rosalind created and x-ray of the double helix - Crick and Watson saw and store the x-ray, creating a 3D model based on their calculations, and were recognized first despite Rosalind initial findings