Chapter 4 Flashcards
1
Q
carbs
A
- primary energy source
- starch, sugars, fiber
2
Q
energy
A
- 4kcal/carb
- need for red blood cells
- need more glucose for exercise
3
Q
monosaccharides
A
- glucose: major monosaccharide, 6c molecule
- fructose: also 6c
galactose: common in food, dairy food
4
Q
glucose
A
- blood sugar
- often bound to another molecule
- added as solo molecule in industry
- mildly sweet
5
Q
fructose
A
- commonly added because sweetest of natural sugars
6
Q
galactose
A
- bonded to glucose, rarely mono
- galactose + glucose = lactose
7
Q
disaccharides
A
- sucrose (glucose + fructose)
- lactose (glucose + galactose)
- maltose (glucose + glucose_: uncommon in food, starch breaks and cleaves into disaccharides
8
Q
monosaccharide chains
A
- oligosaccharides: 3-10
- polysaccharides: 10+
- complex carbs: chains with 3+ monosaccharides
9
Q
complex carbs
A
- long chains of glucose molecules
- starch, glycogen, most fibres
10
Q
starch
A
- plants store carbs as starch
- break down into glucose
- some starch non digestible: resistance starch
- amylose: unbranched
- amylopectin: highly branched (common in veg, legumes,, grains)
11
Q
glycogen
A
- branched chains of glucose
- ban break off and use as quick energy
- need to regulate bgls (liver releases glucose off of glycogen to raise levles)
12
Q
fiber
A
- non digestible chains of monosaccharides
- dietary fiber: natural unprocessed
- functional fiber: added to make food healthier
13
Q
soluble fiber
A
- fruit, legumes, oat, veg, pectin, gum, oat bran mucilge
- absorbs water as it passes gi and forms gel
- delays absorption of glucose
- slows passage of digesta
14
Q
pectins
A
- gel forming polysaccharide
- gives fruit shape
- used in food processing
15
Q
gums and mucilages
A
- gel forming
- holds plant cells together
- guar gum, xanthan gum
16
Q
beta glucans
A
- polysaccharides of branched glucose
- barley and oats
- lower cholesterol
17
Q
insoluble fiber
A
- cereals, grains, legumes, vegetables
- cellulose, hemicellulose, lignin
- attracts water
- speeds up rate of passage of food
18
Q
cellulose
A
- long unbranched chains of glucose
- beta bonds
- indigestible
19
Q
hemicellulose
A
- mixed with cellulose in plant walls
- legumes, veg, nuts
20
Q
lignin
A
- woody part of veg
- non carb dietary fiber
21
Q
chitin
A
- lobsters and crabs
- no known benefits, may cause harm
22
Q
flatulance
A
- some carbs cause
- unfamiliar things to gut
23
Q
oligosaccharides
A
- short chains of monosaccharides
- stachyose: 2 galactose + 1 glucose + 1 fructose
- raffiose: galactose: + glucose + fructose
24
Q
benefits of fiber
A
- adds bulk to stool
- fills you up
- soluble fiber: better metabolic profile, bgl control, lowers cholesterol
- insoluble: helps reduce risk of colon cancer, hernia, ulcerative colitis, hemorrhoids
25
Q
fate of monosaccharides
A
- absorbed from small intestines into blood stream
- travels to liver
- in liver galactose and fructose converted to glucose
- glucose used for energy, stored, released into circulation or subsequent storage
26
Q
small intestine
A
- pancreatic amylase is produced and secreted into duodenum, completes starch digestion, breaks starch to maltose
- brushborder enzyme digest disaccharides: maltase, sucrose, fructose split
27
Q
end products of carb digestion
A
- glucose, fructose, galactose
- absorbed into bloodstream
- converted to glucose by liver
- excess glucose converted to glycogen
- fibers excreted
28
Q
glycosidic bonds
A
- alpha and beta
- if beta bonds not broken htey are attacked which produces gas
- large intestine has some enzymes to break fiber or resistant starch: produces gas and fatty acids
- humans lack enzyme to rbeak raffinose and stahcyose
29
Q
lactose
A
- lactose and lactase: break glucose and galactose
- lactase: enzyme in microvili of small intestine (duodenum) that hydrolyzes lactose
- if you dont produce enough lactase you cant break it down - intolerance
30
Q
what if you are lactose intolerant
A
- can usually tolerate some
- increase tolerance by slowly adding to food
- use lactaide
- use subs
31
Q
functions of carbs
A
- energy sourc e
- regulates bgls: excess glucose stored as glycogen in liver and muscle
- adequate glucose spares protein and prevents ketosis
32
Q
normal insulin secretion and action
A
- eat –> carb breaks into glucose –> bg rises –> beta cells produce insulin –> glucose taken in by cells –> blood glucose drops
33
Q
if you consume digestible carbs
A
- bg rises
- insulin produced in pacreas, anabolic
- pancreas drives glucose into storage
- as insulin produced, longer strains go to glycogen
34
Q
if you dont consume digestible carbs
A
- bg drops
- glucagon released from pancreas (catabolic)
- epinephrine released from adrenal glands
- glycogen in liver broken down and released
35
Q
diabetes
A
- inability to regulate bgls
- type 1 and 2, gestational
- untreated can cause: nerve damage, kidney damage, blindness, peripheral neuropathy, can be fatal
36
Q
type 1 symptoms
A
- frequent urination
- thirst
- hunger
- weight loss
- fatigue
- irritability
37
Q
type 2 symptoms
A
- frequent infections
- blurred vision
- cuts/bruises that are slow to heal
- tingling/numbness in hands/feet
- recurring skin, gum, bladder infections
38
Q
type 1 characteristics
A
- 5-10% of cases
- not enough insulin produced
- cuases bgl to rise to unhealthy level
- requires insulin injections
39
Q
prediabetes
A
- impaired fasting glucose
- impaired glucose tolerance (bg higher than normal but not enough to be diabetes)
40
Q
metabolic syndrome
A
- linked to diabetes and heat disease
- abnormal glucose and insulin levels
- high bp
- excess fat around waist
41
Q
type 2 diabetes mellitus
A
- unclear causes, but genetics, obesity, physical inactivity play roles
- treat with diet, exercise, oral meds
- can progress to injections
- healthy lifestyle choices may prevent or delay type 2 diabetes
42
Q
characteristics of type 2
A
- insulin resistance
- impaired insulin secretion
- islet of langerhans dysfunction (inappropriate responses of beta cells to prevailing bgls)
43
Q
insulin resistance
A
- eat –> carbs + glucose –> bgl up –> insuling –> defective insulin signalling –> decreased glucose uptake by cells –> bgl up
44
Q
glucagon
A
- responds to low glucose
- stimulates breakdown of glycogen to glucose
- stimulates gluconogenesis - production of glucose from amino acids
- causes bg to rise
45
Q
energy not from proteins
A
- cabs spare proteins by preventing breakdown of energy source
- when carb intake low, protiens used for glucenogenesis - production of new glucose
46
Q
glycemic index
A
- ability of food to raise bgl
- low index: dont raise bgl - better for diabetes, higher in fiber, reduce risk of heat disease
- low gi: <55
- med gi: 56-69
- high gi: >70
47
Q
glycemic load
A
GL = gi x amount of available carb/100
48
Q
nutritive vs non nutritive sweeteners
A
- nutritive: provide energy
- non nutritive: no kcal
49
Q
diets in high simple sugars
A
- can cuase dental problems
- associated with increased bad cholesterol
- associated with decreased levels of good cholesterol
- may contribute to obesity
50
Q
hypoglycemia
A
- low blood sugar
- reactive hypoglycemia resuls when too much insulin is produced after a meal
- causes shakiness, sweating, anxiety
