Chapter 4: carbohydrates

Question 1

what are carbohydrates important for?

Answer 1

as an energy resource, especially for the brain

Question 2

what are the 3 monosaccharides?

Answer 2

glucose, fructose, galactose

Question 3

what do the 3 basic monosaccharides combine with to become a disaccharide?

Answer 3

glucose

Question 4

what are the 3 disaccharides?

Answer 4

maltose, sucrose, lactose

Question 5

what is the most abundant carb in diet?

Answer 5

glucose

Question 6

what is the principal form of CHO found in blood? (“blood sugar”)

Answer 6

glucose

Question 7

how is glucose produced?

Answer 7

by plants via photosynthesis

Question 8

describe fructose. where is it found?

Answer 8

sweetest natural sugar; found in fruits, juices, honey, veggies & high-fructose corn syrup

Question 9

what monosaccharide does not occur alone in food? how is it found in food?

Answer 9

galactose; found as a component of lactose

Question 10

polysaccharide

Answer 10

chains of monosaccharides linked together

Question 11

how do plants store glucose?

Answer 11

as polysaccharides in the form of starch

Question 12

can we use starch in the body? what are some great sources of starch?

Answer 12

our cells cannot use complex starch as it exists in plants, we must digest it down to glucose; grains, legumes & tubers are great sources of dietary starch

Question 13

how do animals and humans store glucose?

Answer 13

as glycogen (stored in the liver and muscles)
NOTE: glycogen is not a source of dietary CHO

Question 14

fiber

Answer 14

support structure of leaves, stems, plants

Question 15

dietary fiber

Answer 15

the non-digestible part of plants, fiber found naturally in foods

Question 16

functional fiber

Answer 16

fiber extracted from plants and added to foods and supplements

Question 17

properties of soluble fiber vs insoluble fiber

Answer 17

soluble fiber: dissolves in water, viscous, easily digested by bacteria in colon
insoluble fiber: does not dissolve in water, not fermented by bacteria in colon

Question 18

sources of soluble fiber vs insoluble fiber

Answer 18

soluble fiber: citrus fruits, berries, oats, beans, used to thicken & stabilize foods
insoluble fiber: whole grains and vegetables

Question 19

benefits of soluble fiber vs insoluble fiber

Answer 19

soluble fiber: decrease risk for CVD & type 2 diabetes because it lowers LDL and manages blood glucose
insoluble fiber: promotes regular bowel movements, alleviates constipation, reduce risk for diverticulosis (strain on wall of large intestine)

Question 20

other benefits of fiber

Answer 20

reduce risk of colon cancer, slows movement through GI tract and enhances satiety (promotes weight loss)

Question 21

what is the adequate intake of fiber

Answer 21

14 grams per 1,000 kcal in diet

Question 22

during intense exercise, which macromolecule supplies most energy?

Answer 22

CHO: 2/3 of energy being used

Question 23

ketones

Answer 23

alternate source of energy the brain can use when CHO intake is insufficient

Question 24

what can excessive ketones lead to?

Answer 24

ketoacidosis -> damages tissues

Question 25

where does most digestion of CHOs happen?

Answer 25

small intestine

Question 26

what digests CHOs in the mouth?

Answer 26

salivary amylase

Question 27

what happens to salivary amylase in the stomach?

Answer 27

destroyed by HCl, there is no CHO digestion in the stomach

Question 28

what enzymes break down CHOs in the small intestine?

Answer 28

pancreatic amylase: shorter chains -> maltose maltase: glucose + glucose sucrase: fructose + glucose lactase: galactose + glucose

Question 29

what happens to undigested CHOs in the large intestine?

Answer 29

bacteria ferment the CHO and remaining fiber is excreted in the feces

Question 30

glycogenesis

Answer 30

making glycogen (stored in the liver) don't need glucose right away

Question 31

what is considered normal blood glucose?

Answer 31

70-100 mg/dl

Question 32

what happens to your blood glucose after a meal?

Answer 32

BG increases -> insulin secreted -> BG decreases

Question 33

how does glucagon affect blood glucose?

Answer 33

increases BG

Question 34

what is the recommended dietary intake for CHO?

Answer 34

130g per day just to supply the brain with glucose (45-65% of daily calorie intake)

Question 35

which CHOs should we limit and which should we emphasize?

Answer 35

limit: refined grains and added sugars emphasize: whole grains, fruits, and veggies

Question 36

what is the anatomy of a whole grain?

Answer 36

bran: high in fiber, contains most vitamins and minerals in the grain endosperm: contains most of the CHO and protein in the grain germ: contains healthy fats and vitamins

Question 37

processed grains have which anatomy pieces of the whole grain?

Answer 37

endosperm

Question 38

are added sugars chemically different from naturally occurring sugars?

Answer 38

no, foods that contain added sugars just usually have fewer additional nutrients

Question 39

what affect do sugars have on cholesterol?

Answer 39

increases LDL and decreases HDL

Question 40

diabetes

Answer 40

inability to regulate blood glucose levels

Question 41

what is the fasting blood glucose range for prediabetes? diagnosis of diabetes?

Answer 41

pre: 100-125 mg/dl diabetes: >125 mg/dl

Question 42

type I diabetes

Answer 42

autoimmune disease: body destroys pancreatic cells that make insulin, frequently diagnosed in adolescence, may lead to ketoacidosis if not treated using insulin injections or a pump

Question 43

type II diabetes

Answer 43

develops progressively over time, body cells become unresponsive to insulin, more insulin needed which creates a high demand on the pancreas, most common trigger: obesity

Question 44

increased risk factors for type II diabetes

Answer 44

obesity, physically inactive, poor diet, metabolic syndrome: high waist circumference, high blood pressure, high blood lipids and blood glucose, genetic predisposition, increased age

Question 45

hypoglycemic drugs

Answer 45

increase pancreatic responsiveness -> decrease or slow down glucose absorption -> decrease amount of glucose made by the liver -> increases insulin action (effectiveness)

Question 46

what can chronic hyperglycemia lead to?

Answer 46

nerve damage (diabetic neuropathy), amputation, infections, increased risk of CVD disease, kidney damage (nephropathy), blindness (retinopathy), seizures, death

Question 47

gestational diabetes

Answer 47

occurs during pregnancy, cause unknown, insufficient insulin production or insulin resistance during pregnancy

Question 48

risk factors for gestational diabetes

Answer 48

obese, age 35+, native american, african american, hispanic

Question 49

if blood glucose is not controlled during gestational diabetes, what could happen?

Answer 49

risk of developing large bay (macrosomia), child at risk for overweight later in life, preeclampsia

Question 50

how does gestational diabetes resolve? does it increase risk for development of other types of diabetes?

Answer 50

resolves spontaneously after birth, increased incidence of type II diabetes over the next 5-10 years (mom needs to lose weight gained during pregnancy)