Chapter 41 Flashcards
1
Q
What is nutrition?
A
-the food that we eat and the nutrients they contain
2
Q
What are macronutrients? Examples?
A
- nutrients that we need in larger amounts
- carbs, fats, proteins, water
- sodium, chloride, potassium,calcium
3
Q
What are micronutrients? Examples?
A
- nutrients that we need in very small amounts
- vitamins and minerals
- iron, zinc, cobalt (trace elements)
4
Q
What are essential nutrients?
A
-required nutrients that the body cannot produce
5
Q
What are nonessential nutrients?
A
-nutrients that our body produces
6
Q
What is metabolism?
A
-all chemical reactions in the body
7
Q
What is catabolism?
A
-breaking down molecules into simpler forms
8
Q
What is an exergonic reaction?
A
- produces energy
- catabolic
9
Q
What is anabolism?
A
-building complex molecules from simpler ones
10
Q
What is an endergonic reaction?
A
- consumes energy
- anabolic
11
Q
What is ATP? Function?
A
- adenosine triphosphate
- energy source for the body
12
Q
How is energy transferred to ATP?
A
- oxidation
- reduction
13
Q
What is oxidation?
A
- removal of electrons
- decrease in potential energy
14
Q
What is a dehydration reaction?
A
- loss of hydrogen ions
- oxidation
15
Q
What is reduction?
A
- addition of electrons
- increases potential energy
16
Q
What are coenzymes? Examples?
A
- couple compounds that receive the liberated hydrogens
- nicotinamide adenine dinucleotide (NAD)
- flavin adenine dinucleotide (FAD)
17
Q
What is phosphorylation? What is it used for?
A
-addition of a phosphate group
18
Q
What are the three mechanisms of phosphorylation? Where do they occur?
A
- substrate level: in cytosol; ex. glycolysis
- oxidative: in inner mitochondrial membrane; ex. electron transport chain
- photophosphorylation: in plants and bacteria
19
Q
What is glucose? What is it used for?
A
- preferred energy fuel
- ATP production
- amino acid synthesis
- glycogen synthesis
- triglyceride synthesis
20
Q
How is glucose catabolized?
A
-moves into the cell via secondary active transport or facilitated diffusion
21
Q
Where does glycolysis occur? Why is it anaerobic?
A
- in the cytosol
- does not use oxygen
22
Q
What is the net energy gain of glycolysis?
A
- 2 ATP
- 2 NADH + H
23
Q
What are the two fates of the pyruvic acids?
A
- anaerobic: converted into 2 lactic acids
- aerobic: formation of acetly-coA
24
Q
Where does the formation of acetly-coA occur? What compound does it require?
A
- in the mitochondria matrix
- requires coenzyme A
25
What is the chemical reaction occurring in the formation of acetly-coA? What is the energy net gain
- pyuvate + coenzyme A -> acetyl-coA
- happens twice
- 2 NADH + H
26
Where does the Krebs cycle occur? What is the net energy gain?
- in mitochondrial matrix
- 3 NADH + H
- 1 FADH2
- 1 ATP
27
Where does electron transport chain occur? Why is it aerobic?
- within the inner membrane of the mitochondria
| - requires oxygen
28
What is the role of oxygen in the electron transport chain? Proton pumps? ATP synthase?
- oxygen:
- proton pumps:
- ATP synthesis:
29
What is the net energy gain from the electron transport chain?
-32-34 ATP
30
What is glycogenesis? Where is it stored? What hormone promotes it?
- glucose storage
- in muscle fibers and liver cells
- insulin
31
What is glycogenolysis? What hormones promote it?
- glucose release
| - glucagon
32
What is gluconeogenesis? What hormones promote it?
- new glucose from fats and proteins
| - cortisol
33
How is glucose metabolism controlled? What organs help with this? Hormones and their function?
- pancreas: insulin decreases level; glucagon increases level
- adrenal medulla: epinephrine stimulates glycogenolysis (increases levels)
- adrenal cortex: cortisol stimulates gluconeogenesis (increases levels)
- thyroid gland: thyroid hormone can raise or lower level
- anterior pituitary gland: andrenocortiotropic stimulates release of cortisol; thyroid stimulating hormone stimulates release of thyroid hormone
34
How are lipids transported in the blood?
-as lipoproteins
35
What are the four types of lipoproteins?
- chylomicrons
- very low density lipoproteins
- low density lipoproteins
- high density lipoproteins
36
What is the significance of blood cholesterol? Good? Bad?
-
- good: HDL associated with low incident of heart disease
- bad: high LDL associated with coronary artery disease
37
What is the fate of lipids? What is the distribution of triglyceride storage?
- may be oxidized to produce ATP
- may be stored in adipose tissue and liver
- 50% subcutaneous
- 12% around kidneys
- 10-15% omenta
- 15% genital area
- 5-8% muscles
- 5% behind eyes, sulci of heart, and epiploic appendages
38
How are lipids catabolized?
-lipolysis
39
What is lipolysis? What is it broken down into? What do they then convert into?
- breaking down of triglycerides into gylcerol and fatty acid chains
- glycerol: glucose used in glycolysis
- fatty acids: broken down into acetyl-coA
40
What would happen if lipolysis happened excessively?
- excessive acetyl-coA are formed
| - build up of ketones
41
How are lipids anabolized?
-by lipogenesis
42
What is lipogenesis? When does it occur?
- synthesis of triglycerides, cholesterol, phospholipids, and prostaglandins
- made from glucose and amino acids
- occurs when more calories are consumed than needed
43
How are proteins catabolized?
-
44
What is deamination? Where does it take place?
- removal of amino acids
| - in liver cells
45
What are amino acids converted into? What is their fate?
- ammonia: converted into urea and excreted
| - keto acids: enter krebs, converted into glucose, or converted into fat
46
What hormones stimulate protein catabolism?
-
47
How are proteins anabolized? What do DNA and RNA do?
- by ribosomes in cells
| - DNA and RNA are used as a blueprint
48
What are essential amino acids?
- needed to synthesize proteins
| - 9 that you must get from diet
49
What are nonessential amino acids?
- needed to synthesize proteins
| - 11 that your body can make
50
What hormones stimulate protein synthesis?
- growth hormone
- testosterone
- cortisol
51
What are vitamins? Function?
- organic molecules needed in small amounts for normal metabolism
- act as coenzymes
52
What are fat-soluble vitamins? How is excess handled?
- A, D, E, and K
| - can be stored
53
What are water-soluble vitamins? How is excess handled?
- B and C
| - will be excreted in waste
54
What are minerals? Function?
- inorganic elements of salts
| - regulates enzymatic reactions
55
What is metabolic rate?
-amount of energy released in the body in a given time
56
What is basal metabolic rate? What influences it?
- measurement of metabolic rate when body is in quiet, resting, fasting condition
- size, composition, gender, age, temperature, drugs, thyroid hormone
57
What is total metabolic rate? What is included?
- amount of energy used or expended by the body at a given time
- basal metabolic rate
- energy used for skeletal work
- thermic effect of food
58
What is energy input?
-total calories ingested per day
59
What is energy output?
-total calories expended per day
60
How does weight relate to energy input/output?
- weight remains constant when they equal each other
- more output = weight loss
- more input = weight gain
61
How is food intake regulated?
- hypothalamus
| - appetite and satiety center
62
What is the appetite center?
-stimulation = increased appetite
63
What is the satiety center?
-stimulation = decreased appetite
64
What stimulates the appetite and satiety center?
- temperature
| - blood glucose concentrations
