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Biochemistry Post Midterm > Nutrition > Flashcards

Flashcards in Nutrition Deck (45):
1

what are the 2 functions of nutrients?

provide energy - macronutrients
"essential" molecules

2

what make up the macromolecules?

carbs
fats
proteins

3

what make up the essential molecules/micronutrients?

vitamins
minerals
essential aa
essential fatty acids

4

what 3 factors make up the dailt energy expendature (DEE)?

1.BMR/RMR
2.physical activity
3.energy required to process food (thermogenesis)

5

what factors affect RMR/BMR?

gender
body temperature
environmental temperature
thyroid function
pregnancy/lactation
age

6

what is Diet-induced Thermogenesis (DIT)?

the energy required to digest, absorb, distribute and store nutrients - about 10% of RMR/day

7

what are the percentages of caloric intake from macronutrients?

carbs - 50% - most important
Fat - 30%
protein - 20%

8

what is the energy contribution of carbohydrates, protein, fat and alcohol (kcal/g)?

4
4
9
7

9

what are the 3 categories of carnohydrates?

monosaccharides
disaccharides
polysaccharides

10

what are sources of monosaccharides?

glucose
fructose
- fruits, sweet corn, corn syrup, honey

11

what are sources of dissaccharides?

sucrose - table sugar
lactose -milk sugar
maltose - in beer and malt liquors

12

what makes up sucrose?

glucose and fructose

13

what makes up lactose?

glucose and galactose

14

what makes up maltose?

glucose and glucose

15

what are sources of polysaccharides?

complex carbs - polymers of glucose
do NOT have a sweet taste
Starches - found in plants
-wheat, grains, potatoes, dried peas, beans, vegetables.

16

how are polysaccharides classified?

base on how they affect blood glucose levels

17

what is glycemic index?

time course of rise and decline of blood glucose after a meal

18

what does fiber contain?

non-digestable carbs
includes cellulose, lignin, pectin
Does not provide energy

19

what could too much fiber do?

decrease absorption of fat-soluble vitamins and bind to trace elements like zinc

20

what are the most important class of dietary fat from an energy perspective?

TAGs

21

what percentage of total dietary lipid does TAGs contribute?

90%

22

which plant sources do not have a source of unsaturated FA (good kind) and more saturated (bad)?

coconut oil
pal oil exceptions
maybe good for skin

23

what provides the essential FA?

linoleic and alpha linolenic acids

24

when does arachidonic acid become essential?

if or when linoleic acid is insufficient/deficient

25

what are EFA required for?

membrane fluidity and synthesis of eicosanoids

26

what are deficiency of EFAs characterized by (not common)?

scaly dermatitis
hair loss
poor wound healing

27

whats the general dietary goal when it comes to fats?

decrease saturated fat (TAGs)
increase mono or poly unsaturated FA

28

what cannot be stored?

amino acids

29

what is the function of proteins?

replenish body proteins
required for essential aa

30

what proteins have a high biological value?

proteins from animal sources

31

what does high biological value mean?

contain high amounts of essential aa required for synthesis of human tissue

32

what has a low biological value?

gelatin

33

when is nitrogen intake greater than nitrogen excretion [positive nitrogen balance]?

when tissue growth is occurring - growing kids, pregnancy, during recovery from surgery/trauma

34

what balanceare healthy individuals in?

nitrogen balance

35

when is nitrogen excretion greater than nitrogen intake [negative nitrogen balance]?

inadequate deitary protein
lack of essential aa
physiology stress - trauma, burns, illness, surgery

36

what are some diseases greatly influenced by?

diet

37

what is the major contributor of serum cholesterol?

LDL - from TAGs and VLDL

38

what kind of effect does reducing dietary cholesterol have on serum cholesterol?

little effect!

39

how can you reduce serum cholesterol?

1. reduce saturated FA (TAGs), increase mono and poly unsaturated FA
2. decrease de novo synthesis of cholesterol by statins or something else

40

what are the long term signals of hormonal regulation of weight and energy?

leptin
insulin

41

where is leptin produced? what is it?


adipose tissue

produced proportionally to fat cell density and plays a key role in weight gain, appetite suppression and energy expenditure through its actions on the HYPOTHALAMUS!

it also regulated inflammatory responses, blood pressure and bone density

42

what does insulin do?

similar to leptin
dampens appetite by exerting its effects on the HYPOTHALAMUS

43

what are the short term signals of hormonal regulation of appetite?

ghrelin
CCK

44

what is Ghrelin?

secreted by endocrine cells of stomach
increase the release of NPY - which enhances appetite and food intake

ghrelin release is activated by fasting and low glucose

inhibited by high glucose

45

what is CCK

+ PPY cause satiety during a meal and transmit those signals to the HYPOTHALAMUS