final exam bio

Question 1

metabolism

Answer 1

bio chem runs that allow cell/organism to extract energy from its surroundings and use it for homeostasis, growth and reproduction

Question 2

organic molecules

Answer 2

carbohydrates, lipids, proteins, nucleic acids

Question 3

monosaccharides

Answer 3

main fuel cells use for work
in aqueous solns can form rings

Question 4

disaccharide

Answer 4

consists of 2 mono linked via dehydration rxn
sucrose = glucose + fructose
lactose = glucose + galactose
maltose = 2 glucose

Question 5

polysaccharides

Answer 5

polymers of monosaccharides
long chains of sugar units
starch: long chain of glucoses (plants)
glycogen: same but with branches (animals, muscle)
cellulose: same but with different linkage (cell walls of plants, structural component) (most abundant) (dietary fiber)

Question 6

lipids

Answer 6

• C and H linked by nonpolar covalent bonds, so mostly hydrophobic and insoluble in water
  fats, phospholipids, steroids

Question 7

fats

Answer 7

type of lipid
- dietary fat composed mostly triglycerides
- made from glycerol + 3 fatty acids (bound by dehydration rxn)
function: energy storage, cushioning, insulation

Question 8

unsaturated fats

Answer 8

fewer than max # of H bonded to the C resulting in a double bond (bend in fatty acid chain)
- lower melting point (oils)
- liq @ room temp (plants/fish triglycerides)
mono/poly depending on how many double bonds (trilinolein)

Question 9

saturated

Answer 9

all C’s of the fatty acid backbone are bonded to max # of H
- solid @ room temp
- animal triglycerides
- easily stack

Question 10

atherosclerosis

Answer 10

lipid containing deposits (plaque) build up in walls of blood vessels, reduce blood flow
- saturated fat diet leads to this

Question 11

essential nutrients

Answer 11

differ from animal to animal,
- substances animals require in diets but can’t make for themselves
- essential amino acids, fatty acids, minerals and vitamins
human requirement:
- 8 essential amino acids
- 13 vitamins (water and fat soluble)
- large # of essential minerals (macro/micronutrients and trace elements)

Question 12

8 essential amino acids

Answer 12

methionine
tryptophan
leucine
phenylalanine
threonine
valine
isoleucine
lysine

Question 13

vitamins (water v fat soluble)

Answer 13

water soluble
- often precursors of coenzymes
- coenzymes: non protein organic subunits that associate with/ enzymes to aid in catalysis
riboflavin B2 -> FAD component
niacin -> NAD+

fat soluble
- variety roles
vitamin A -> visual pigment

Question 14

minerals

Answer 14

ions (neurons, muscle contraction), structural material (calcium), parts of other molecules (iron in hemoglobin)

Question 15

how does digestion work? + digestive structures common to all mammals

Answer 15

• food is pushed through digestive tube by peristalsis (muscular contractions of wall)
• 4 lvls of gut
• storage of food @ locations in tube allows for digestion while engaged in other activities

structures common to all mammals
- mouth, pharynx, esophagus, stomach, intestine, anus

Question 16

stomach

Answer 16

stores food + continues digestion
secretes mucus and gastric juice

Question 17

small intestine

Answer 17

completes digestion and begins absorption of nutrients
- nutrients absorbed many are processed in the liver

duodenum receives secretions from liver, gallbladder, and pancreas

Question 18

large intestine

Answer 18

primarily absorbs water and mineral ions from digestive residues

• secretes mucus and bicarbonate ions, concentrates undigested matter into feces

Question 19

sphincter

Answer 19

ring of smooth muscle form valves between major regions of digestive tract
ex.
lower esophageal sphincter: between esophagus and stomach
pyloric sphincter: between stomach and small intestine

Question 20

where does digestion start?

Answer 20

mouth more specifically salivary glands (secrete lubricating mucus, amylase enzyme, starch digesting enzyme + lysozyme, kills bacteria, and bicarbonate ions)

Question 21

liver

Answer 21

secretes bile, which emulsifies fats, and bicarbonate ions

Question 22

gallbladder

Answer 22

stores and concentrates bile secreted by liver

Question 23

pancreas

Answer 23

secretes enzymes that break down all major food molecules and bicarbonate ions that neutralize digestive contents

Question 24

rectum

Answer 24

stores feces, distensión stimulates expulsion of feces

Question 25

4 major layers of the vertebrate gut

Answer 25

1. mucosa
2. submucosa
3. muscularis
4. serosa

Question 26

mucosa

Answer 26

lines inside of gut
epithelial cells that absorb nutrients, seal off digestive contents from body fluids
glandular cells: secrete enzymes, mucus, pH regulation

Question 27

submucosa

Answer 27

elastic connective tissue, neuron network, blood + lymph vessels
neural network: local control of digestive activity

Question 28

muscularis

Answer 28

formed by circular layer (constricts gut diameter) and longitudinal layer (shortens + widens gut)m, does peristalsis
- oblique layer (stomach only)

Question 29

serosa

Answer 29

outermost gut layer, connective tissue that is continuous w/ mesentery (tissue that suspends dig organs in abdomen)
secretes lubricating fluid to reduce friction between organs

Question 30

chyme

Answer 30

partially digested food

Question 31

bolus

Answer 31

food mass from mouth

Question 32

epiglottis

Answer 32

blocks trachea when swallowing

Question 33

swallowing reflex

Answer 33

• elevation of soft palate to prevent food bolus from entering nasal passages
• pressure of tounge seals back of mouth and prevents bolus from backing up
• larynx moves upward, pushing glottis against epiglottis to prevent bolus from entering airway

Question 34

glottis

Answer 34

middle part of larynx, where vocal cords are located

Question 35

gastric juice

Answer 35

hydrochloric acid and protein digesting enzyme, pepsin + mucus (secreted by glandular cells)

Question 36

chief cells

Answer 36

secrete pepsinogen (precursor to pepsin)
positive feedback mechanism

Question 37

parietal cells

Answer 37

secrete H+ and Cl-
HCL can activate pepsinogen to form pepsin

Question 38

gastric pits

Answer 38

indentations in stomach that contain
surface epithelial cells, mucous cells, chief cells, and parietal cells

Question 39

what stimulates release of secretion of cells

Answer 39

when food enters stomach, stretch receptors in stomach wall are activated

Question 40

gastrin

Answer 40

major hormone that regulates acid secretion in the stomach
- stimulated by stomach distension + presence of digested proteins (amino acids)

Question 41

stomach pH

Answer 41

2: optimal pH for pepsin
- helps unfold and break down proteins
- kills unwanted bacteria

Question 42

function of stomach mucus

Answer 42

protects stomach wall from acidity and breakdown from pepsin

Question 43

how long does it take for the stomach to empty after a meal? which nutrient takes the longest to digest and where is it digested?

Answer 43

1-6 hours
fat - small intestines

Question 44

where does the most digestion occur?

Answer 44

small intestine

Question 45

how are proteins/polysaccharides/triglycerides/nucleic acids broken down in small intestine?

Answer 45

proteins: endopeptidases, exopeptidases
polysaccharides: hydrolysis by amylase (from pancreas), then disaccharidases
triglycerides: hydrolyzed by lipase
nucleic acids: hydrolyzed by nucleases (DNase, RNase)