Midterm 2 Flashcards
(144 cards)
1
Q
What cells must use glucose as an energy source?
A
Neurons and RBCs
2
Q
In what form is glucose stored in the body
A
Glycogen
3
Q
Where is glucose stored in the body
A
some stored in the liver, a lot is stored in the muscels
4
Q
Where is glucose released from when needed in the blood
A
Hydrolyzed from glycogen in the liver, glycogen in the muscle isn’t released back into the blood stream
5
Q
What happens if excess glucose enters the body
A
either used for energy or converted to fat in the liver
6
Q
Def: Gluconeogenesis
A
conversion of certain amino acids to be used for energy
7
Q
What occurs in ketosis
A
fat is used to provide fuel when CHO isn’t low, fat fragments join to from ketone bodies which can be used to fed the brain
8
Q
What hormones regulate blood glucose homeostasis
A
Insulin which causes glucose to move into cells and glucagon which promotes glucose from the liver to move into the blood
9
Q
How do blood glucose hormones promote uptake or release
A
bind to liver and if uptake muscle cells too
10
Q
Negative feedback loop of blood glucose homeostasis
A
- a person eats, blood glucose rises
- High blood glucose stimulates the pancreas to release insulin
- Insulin stimulates the uptake of glucose into the cells to store it as glycogen and the conversion of excess into fat for storage
- As the body’s cells use glucose, blood levels decline
- low blood glucose stimulates the pancreas to release glucagon into the blood stream
- Glucagon stimulates liver cells to break down glycogen and release glucose into the blood
- Blood glucose begins to rise
11
Q
Def: Type 1 diabetes
A
Genetic form of diabetes, individual is unable to produce insulin
12
Q
Def: Type 2 Diabetes
A
Caused by obesity and certain type of excess fat, individual is unable to respond to insulin creating a positive feedback loop
13
Q
Def: Hypoglycemia (and what symptoms it causes)
A
Low blood sugar, caused by an excess of insulin in the blood stream, often a result of poorly managed diabetes. Can cause weakness, rapid heartbeat, sweating, anxiety, hunger, and trembling
14
Q
Def: Hyperglycemia
A
High blood sugar, high amount of glucose stuck to RBCs, causes damage to tissues, heart disease and stroke, neural problems, vision and hearing loss, infections, amputations, kidney failure
15
Q
Def: Oral Glucose tolerance test
A
Assesses your ability to handle a glucose load and regulate blood sugar
16
Q
Process of a Oral Glucose Tolerance Test
A
- Overnight fast
- Ingestion of 75g of glucose as an oral load
- blood glucose response measured over 2-3h
- Often accompanied by hormonal measurements
17
Q
Def: Glycemic Response
A
Speed of glucose absorption, blood glucose rise, and speed of return to normal
18
Q
Def: Glycemic Index
A
Flood classification based on glycemic response, high index = greater glycemic response = more sugar
19
Q
Def: Glycemic Load
A
Glycemic index x carbohydrate amount
20
Q
What are the common harms of sugar
A
- Nutrient deficiencies: Displace calories that contain nutrients
- Dental caries: Sugars fermented to acid by bacteria erodes enamel on teeth
21
Q
Factors that increase negative effects of sugar on teeth
A
Time in mouth, sticky foods, frequency of consumption
22
Q
Why is sugar seen to make childern hyperactive
A
Parental expectations and often associated with events that promote hyperactivity
23
Q
What are the recommended intakes of sugar
A
No UL, No more than 25% of total daily intake,
less than 10% is good, less than 5% is better
24
Q
Def: Artificial Sweeteners
A
Non-nutritive sweeteners, moderate dose is considered safe, high does may cause protentional negative health effects
25
Stevia
A herbal sweetener, accepted by health canada
26
Sugar Alcohols
Nutritive (0.2 to 4 kcal/g), no dental caries, low GI, Side effects in large quantities, absorbed slowly
27
What is the negative effect of sweeteners
Reduces sensitivity to sweetness causing excess caloric intake in the future
28
Soluble Fiber
Lowers cholesterol by binding bile, slows glucose absorption, slow transit of food through upper GI tract
29
What are the health benefits of soluble fiber
lower risk of heart disease, lower risk of diabetes and lower risk of colon cancer
30
Insoluble Fiber
Increases fecal weight and speed fecal passage through colon, provides feelings of fullness
31
Health benefits of insoluble fiber
May help with weight management
32
Harmful effects of fiber
Limit ability to meet caloric intake needs, sudden introduction can cause abdominal discomfort, gas and diarrhea
33
DRI for Carbohydrates
RDA 130g, AMDR 45-65%
34
Daily fiber intake
25g/2000kcal, DRI 14g per 1000kcal per day
35
Fiber intake limits
WHO advises less than 40g
36
Def: Obesity
One who receives negative health affects due to high body weight and body fat
37
Obesity as a health indicator
Inaccurate on individual level, good indicator on a average health level
38
What are Lipids composed of
Carbons, hydrogen and oxygen
39
What are the uses of fat
Insulation, energy (low intensity), protection, taste for food
40
What is the structure of fats?
Even number of Carbons (usually 18) with H attached, carboxylic acid and methyl group
41
What is considered to be a long, medium and short chain
Long: 12-24
Medium: 6-10
Short: less than 6
42
Def: Saturated Fatty acids
No double bonds, as many H as possible, solid at room temperature, more stable, longer chain lengths
43
Def: Unsaturated Fatty Acids
Lose of at least 2 H atoms, liquid at room temperature, unstable, shorter chains
44
Def: Monounsaturated Fatty Acids
1 double bond
45
Def: Polyunsaturated fatty acid
2+ double bonds
46
Stearic Acid
18 Carbon Atoms, 0 Double bonds, saturated, Most animal fats
47
Oleic Acid
18 Carbon Atoms, 1 Double bonds, Monounsaturated, Olive, canola oils
48
Linoleic acid
18 C, 2 Double bonds, polyunsaturated, sunflower, safflower, corn and soybean oils
49
Linolenic Acid
18 C, 3 double bonds, polyunsaturated, soybean, flaxseed, and canola oils, walnuts
50
Omega Number
Location of double bonds nearest to the methyl end of the carbon chain
51
Triglycerides
Glycerol backbone + 3 fatty acids
52
What type of reaction is used to form triglyerides
condensation reaction where H2O is released
53
Hydrogenation
H atoms added to unsaturated fatty acids, makes liquid fat more solid at room temperature, increases shelf life
54
Trans Fatty Acids
Derived from the process of hydrogenation, occurs naturally in some animal-based products, behave like saturated fats in the body
55
Phospholipids
Glycerol + 2 FA + phosphate group, soluble in fat and water, emulsifier
56
Sterols
Multiple-ring structure, eg. Cholesterol and plant sterols
57
Lipid Digestion in the Mouth
Lingual Lipase secreted
58
Lipid Digestion in the Stomach
Lingual Lipase activated by acid and begins to digestion hydrolyze one bond of triglycerides to produce diglycerides and fatty acids, the stomach churning action mixes fat with water and acid
59
Lipid Digestion in the Small intestine
CCK signals release of bile which emulsified fat, pancreatic lipase hydrolyzes emulsified into monoglycerides, glycerol and fatty acids
60
Lipid Digestion in the Large intestine
some fat and cholesterol trapped in fiber, exit in feces
61
Emulsification by bile
1. Fat and water separate with enzymes in the water,
2. Bile has an affinity for both fat and water allowing it to bring the fat into the water as a micelle
3. Bile converts large fat globules into small droplets
4. exposes fats to enzymes
62
How are Triglycerides digested
Pancreatic and intestinal lipases hydrolyze the fatty acids
63
How are phospholipids digested
Pancreatic and intestinal lipases hydrolyze the fatty acid chains
64
How are sterols digested
Sterols are absorbed in their whole form
65
How is Glycerol absorbed
Diffuses directly into the blood stream
66
How are small lipids absorbed
Diffuses directly into the blood stream
67
Which forms of lipids can diffuse directly into the blood stream
Glycerol and small lipids
68
How are monoglycerides and fatty acids absorbed?
1. combine with bile to form micelle
2. Diffuse across membrane
3. Reform triglycerides
4. Combined with other lipids (cholesterol, phospholipids) and protein to form chylomicrons
5. Chylomicrons enter the lymph
69
What types of fats are absorbed via combination with bile to form micelles
Monoglycerides and fatty acids
70
Def: Chylomicrons
Clusters of lipids and proteins that act as transport vehicles for fat called lipoproteins
71
Types of lipoproteins
Chylomicrons - large and least dense
VLDL (very-low-density lipoprotein) - bad
LDL (Low density lipoprotein)
HDL (high density lipoprotein) - good
72
Structure of a typical lipoprotein
The interior is composed of triglycerides and cholesterol and is surrounded by phospholipids
Phospholipids are organized similar to membranes (heads on the outside, tails on the inside)
73
Composition percentage of Chylomicron
Primarily triglycerides very little protein
74
Composition percentage of VLDL
Half triglycerides, relatively equal composition of other nutrients
75
Composition percentage of LDL
lots of cholesterol relatively equal composition of other nutrients
76
Composition percentage of HDL
Lots of proteins, least amount of triglycerides, equal parts of cholesterol and phospholipids
77
Similarities in VLDL and HDL
Same percentage composition of cholesterol and phospholipids in both
78
Function of Chylomicrons
Transport diet derived lipids to cells
79
Function of VLDL
Produced in liver, Deliver lipids to body (from GI tract and chylomicron remnants)
80
Functions of LDL
VLDL that has many triglycerides removed, High in cholesterol (delivers it to tissues)
81
Functions of HDL
Produced by liver to remove cholesterol from body tissues and back to liver for recycling, also has an anti-inflammatory property
82
Lipoprotein lipase
Enzyme that is activated in response to insulin, hydrolyzes triglycerides to glycerol and fatty acids, allowing TG to move into the cells on the endothelial cell lining of the capillaries around muscle adipose and heart tissue
83
Factors that lower LDL and/or raise HDL
```
Weight control (body composition)
Monounsaturated or polyunsaturated fat in diet (instead of saturated)
Soluble dietary fibers
Phytochemicals (e.g. plant sterols)
Moderate alcohol consumption
Physical activity (mainly raise HDL)
```
84
Blood Cholesterol effects of heart attacks
Accumulates in arteries, restricts blood flow, leads to heart attack or stroke
85
Process of Atherosclerosis
1. Damage to artery wall
2. Deposition f oxidized LDL
3. Inflammatory response
4. Recruitment of monocytes to damages area with inflammatory response turning them into macrophages to ingest the LDL cholesterol
5. Macrophages accumulate in arterial intima (take up lots of cholesterol turning them into foam cells
6. Collagen deposition around foam cells ( thickening and hardening of the intimal medial layer of artery)
7. Migration of smooth muscle cells forming a fiberous cap
8. Artery becomes hard and non-elastic
86
Effects of Saturated Fat, trans fats and cholesterol consumption
Increased risk of heart disease
87
Effects of mono- and poly- unsaturated fat consumption
decreased risk of heart disease, larger chylomicrons/ VLDL preventing them from crossing the endothelium layer
88
Fat DRI
20-35%
89
Daily values for various fats
65g or 30% of total energy intake fats
20g or 10% of total energy intake for saturated and trans fats - low as possible
300mg cholesterol
90
Roles of Adipose tissue
Stores fat - creating unlimited energy store
Secrets hormones: adipokines - regulates energy balance and influence body functions
Insulation
shock absorption
structural material for membranes
91
Essential Fatty Acids
Linoleic Acid
Linolenic Acid
Eicosanoids
92
Linoleic Acid
Omega-6 - component of membrance phospholipids, required for nerves, makes arachidonic acid
93
Linolenic Acid
Omega-3 - Component of membrane phospholipids make EPA and DHA - needed in eyes and brain
94
Eicosanoids
Made from n-6 and n-3 long-chain fats, inflammatory mediating compounds (n-6 inflammatory and n-3 anti-inflammatory
95
Olive Oil
Low total and LDL cholesterol, low LDL oxidation, Lower blood clotting factors, Phytochemicals that acts as antioxidants, Lower BP, Lower inflammation
96
Nuts
Energy dense, mono- and polyunsaturated fats, Fiber, protein, and other compounds, phytochemicals that act as antioxidants, plant sterols
97
Fish
EPA and DHA -long chain fats
| Reduce blood TG, Lower blood pressure, preventing blood clots, defending against inflammation, precursors for eiosanoid
98
Mediterranean Diet
High fat, low saturated fat, very low in trans fat
99
Effects correlations of a Mediterranean diet
lower risk of heart disease, lower risk of cancer
100
Functions of proteins
Building blocks of the body
Enzymes
Hormones
101
Where can you get protein from
Meat, eggs, milk, legumes, grains, vegetables
102
Amino acid structure
Contain C,H,O, & N, central carbon with an acid group (COOH) and an amino group (NH2), a unique side chain and hydrogen saturation
103
How many essential and none essential amino acids are there
9 essential, 11 non-essential
104
What is the bond between amino acids called when forming a chain
peptide bond
105
Primary Structure
Sequence of amino acids
106
Secondary Structure
Determined by week electrical attractions within chain, resulting in either a twisting or folding of protein
107
Tertiary Structure
Complex structures as a result of side chain properties
108
Quaternary sturcture
Interactions between polypeptide chains
109
Protein Denaturation
A proteins stability is disturbed causing it to uncoil and lose their shape along with a loss of functional ability - could be caused by heat or acid
110
Digestion of protien in the mouth
Mechanical digestion through mastication
111
Digestion of protein in the stomach
Hydrochloric acid denatures protiens and activates pepsinogen to pepsin where cleaves proteins into smaller polypeptides
112
Digestion of protein in the small intestine
Pancreatic and intestinal proteases turn polypeptides into tripeptides, dipeptides and amino acids, surface enzymes such as intestinal tripeptidases and dipeptidases further break down into amino acids
113
Protien Absorption
Amino acids transported into intestinal cells -Specific carriers for amino acids and small peptides
Once in the enterocyte they are used for energy and synthesis of other proteins
Unused AA are sent to the liver via the bloodstream
114
Transcription
DNA acts as a template for mRNA which copies the information
115
Translation
mRNA leaves the nucleus and attaches amino acids in sequence based on mRNA until completed chain is released as a protein
116
Roles of proteins
Building materials, Hormones, enzymes, transporters, fluid balance, acid-base balance, antibodies, provide glucose and energy, other
117
Role of protein as a building material
For growth, maintenance or repair, muscle, bone, skin
118
Role of protein as a hormone
Messenger molecules, released in response to stimuli, travel in bloodstream to tissues, elicit appropriate responses
119
Role of protein as an enzyme
Proteins that facilitate or help a reaction to completion - Build substances, break them down transform one substance into another
120
Role of protein as transporters
Transport solutes across cell membranes
121
Def: Gluconeogeneses
Conversion of proteins to glucose
122
Def: Transamination
Conversion of an amino acid to anther amino acid
123
What can amino acids be used to make?
Other compounds - neurotransmitters
| Energy and glucose
124
Deamination
Removal of the N-containing amino groups, resulting in Ammonia (NH3) and keto acid
125
What happens when ammonia is removed form an amino acid
Ammonia is combined with CO2 in the liver to make urea since ammonia is toxic, urea is released into the blood and passes through the kidneys where it is filtered out
126
Protein Turnover
Continual making and breaking of proteins, turnover rate is about 1-2%/day
127
Amino Acid pool
Floating amino acids that are cycled through protein turnover or used for energy
128
Nitrogen balance
N intake - N output = N Balance
129
Positive Nitrogen Balance
Used to gain muscle of build tissues, when more N is going in than coming out, pregnant mom, growing child
130
Nitrogen Equilibrium
Equal N in and out, regular nongrowing individual
131
Negative Nitrogen balance
More N out than in, lose muscle mass, surgical patient or astronaut
132
Factors effecting nitrogen balance
Protein consumption, nitrogen in urine, feces, hair, nails, sweat, skin debris, breath
133
How is nitrogen balance often miscalculated
overestimated N intake, underestimated N output, overall overestimated N balance
134
Protein turnover cycle
1. Eating acts as an anabolic stimulus
2. Muscle protein synthesis rate increases and MP breakdown decrease
3. without stimulus MSP will eventually drop and MPB will eventually rise
135
How does age effect protein turnover cycle
Elderly exhibit the same MPB as adults but lower MPS
136
How does resistance training effect protein turnover cycle
Increases MPS overall for the rest of the day
137
Do athletes require more protein for energy
Amino acid oxidation contributes to less than 5% of energy production during exercise in trained athletes, protein consumption during exercise does not improve performance
138
Do athletes who do resistance training need additional protein
At 0.8g/kg/d in negative protein balance, at 1.4g/kg/d in positive protein balance, at 2.4g/kg/d in very positive protein balance, there is seen to be a significant improvement in strength gains in trained athletes with higher protein intake and overall athletes
139
Optimal Protein intake for resistance training
at least 1.6g/kg/d with a confidence interval of 1.1 - 2.2
140
Protein RDA for endurance athletes
1.2-1.4g/kg/d
141
Protein RDA for team sports
1.2-1.7g/kg/d
142
Protein RDA for power
1.5-1.7g/kg/d
143
Protein RDA for strength
1.6-1.7g/kg/d
144
Protein for Energy restriction
2.0g/kg/d (lose weight while building muscle mass)
