Energy Balance I - Macronutrients Flashcards
1
Q
Nutrition:
A
total of the processes of ingestion, digestion, absorption, and metabolism of food and the subsequent assimilation of nutrient materials into the tissues
2
Q
Nutrient:
A
a substance found in food that performs one or more specific functions in the body
3
Q
The food we eat is part of our _____ and contains ____.
A
- nutrition
- nutrients
4
Q
Food provides nutrients that have one or more _____ or _____ functions in the body.
A
- physiological
- biochemical
5
Q
Nutrients are usually divided into 6 different categories:
A
- carbohydrates
- fats
- proteins
- vitamins
- minerals
- water
6
Q
Nutrients for which the daily intake is more than a few grams are referred to as _____.
A
macronutrients
7
Q
4 macronutrients:
A
- carbohydrate
- fat
- protein
- water
8
Q
3 micronutrients:
A
- vitamins
- minerals
- trace elements
9
Q
Nutrients that are needed in only small amounts (less than 1 g/day) are referred to as _____.
A
micronutrients
10
Q
Most nutrients are ______.
A
micronutrients
11
Q
3 functions of nutrients:
A
- promotion for growth and development
- provision of energy
- regulation of metabolism
12
Q
Growth and development function of nutrients is mainly performed by _____.
A
protein
13
Q
____, ____ _____, and ____ consist largely of proteins, and proteins are required for any ____ ____ or ____.
A
- muscle
- soft tissues
- organs
- tissue growth
- repair
14
Q
_____ and _____ are important building blocks for the skeleton.
A
- calcium
- phosphorus
15
Q
Provision of energy function of nutrients is mainly performed by ____ and ______.
A
- carbohydrate
- fat
16
Q
Although protein can also function as fuel, its contribution to EE is usually _____.
A
limited
17
Q
Nutrients used for the regulation of metabolism:
A
- vitamins
- minerals
- protein
18
Q
Enzymes:
A
proteins that play an important role as catalysts that allow metabolic reactions to proceed at far higher rates than they would spontaneously
19
Q
The interaction between _____, _____, and _____ in the regulation of metabolism can be complex.
A
- vitamins
- minerals
- proteins
20
Q
Ex. of an enzyme:
A
- phosphorylase: breaks down carb stores in liver and muscles
- hemoglobin: found in erythrocytes (RBC)
21
Q
Describe the hemoglobin molecule. Complex of….
A
- protein (polypeptide chains)
- non protein groups (porphyrin rings) that hold iron (to which oxygen molecules can be bound)
22
Q
Macronutrients are molecules that provide _____.
A
energy
23
Q
The general formula of a carbohydrate is:
A
CH2O
24
Q
A carbohydrate can be one or a combination of many of these _____ units.
A
CH2O
25
4 types of carbohydrates:
- monosaccharides
- disaccharides
- polysaccharides
- fibre
26
Saccharides =
sugars
27
Examples of mono and disaccharides:
- sugar
- fruit juices
- fruits
- sweetened cereals and baked goods
- jam
- candy
- chocolate
28
Examples of polysaccharides:
- starches
- cereal
- potatoes
- pasta
- rice
- bread
29
Examples of fiber:
- whole grain cereals
- oats
- fruits
- vegetables
30
Glycogen is a ______. It is stored in _____ and _____.
- polysaccharide
- liver (80-100 g)
- skeletal muscles (300-900 g)
31
Glycogen is the storage form of _____ in animals, including humans.
carbohydrate
32
Dietary fibre comprises the _____ parts of plants that ____ broken down and absorbed in the _____ ____ _____.
- edible
- are not
- human gastrointestinal tract
33
Fibre = ____ plant _____.
structural plant polysaccharides
34
The human small intestine has no ____ to break down these _____ (fibre) and thus they ______ be digested.
- enzyms
- polysaccharides
- cannot
35
Dietary fibre is often divided into:
- soluble fibre
| - insoluble fibre
36
Insoluble fibre:
possesses water attracting properties that help increase bulk, soften stool, and shorten transit time through the intestinal tract
37
Soluble fibre:
undergoes metabolic processing through fermentation and yields end products that have broad, significant health effects
38
Examples of insoluble fibre:
- whole grain foods
- bran
- nuts
- seeds
- vegetables (green beans, cauliflower, zucchini, celery)
- skins of some fruits (tomatoes)
39
Examples of soluble fibre:
- legumes
- oats
- rye
- barley
- some fruits and fruit juices (prune, plums, berries)
- vegetables (broccoli, carrots)
- root vegetables (potatoes, onions)
40
6 metabolic pathways of carbohydrate metabolism:
- glycogenesis
- glycogenolysis
- glycolysis
- gluconeogenesis
- tricarboxylic acid cycle
- pentose phosphate pathway
41
Glycogenesis:
synthesis of glucose
42
Glycogenolysis:
breakdown of glycogen
43
Glycolysis:
oxidation of glucose
44
Gluconeogenesis:
production of glucose from non-carb intermediates
45
Tricarboxylic acid cycle:
- Krebs cycle
| - oxidation of pyruvate and acetyl CoA to CO2 and H2O
46
Pentose phosphate pathway:
production of pentose phosphates and nicotinamide adenine dinucleotide phosphate (NADPH)
47
*See chart
-
48
Fat or lipids are compounds that are _____ in ______ solvents such as _____, _____, and ______.
- soluble
- organic
- acetone
- ether
- chloroform
49
Oil is ____ at room temperature.
liquid
50
Fat is ____ at room temperature.
solid
51
Lipids are molecules built of:
- carbon
- hydrogen
- oxygen
52
Lipids have little ____ relative to ____ and ____.
- O
| - C and H
53
Typical structure of fatty acid is:
16 C, 32 H, and 2 O
54
Simple lipids type:
- neutral fats
| - waxes
55
Examples of simple liquids:
- neutral fats: triacylglycerol
| - waxes: beeswax
56
Compound lipids type:
- phospholipids
- glycolipids
- lipoproteins
57
Examples of compound lipids:
- phospholipids: lecithins
- glycolipids: cerebrosides
- lipoproteins: chlomicrons
58
Derived lipids type:
- fatty acids
- steroids
- hydrocarbons
59
Examples of derived lipids:
- fatty acids: palmitic acid
- steroids: cholesterol
- hydrocarbons: terpenes
60
Triacylglycerols =
- triglycerides
| - the most abundant dietary lipids consumed humans
61
Triglycerides are composed of ....
1 glycerol backbone esterified with 3 fatty acids
62
Triglycerides differ in their ____ _____ composition.
fatty acid
63
Lipids in the human body include...
- fatty acids
- triacylglycerols
- lipoproteins
- phospholipids
64
Fatty acids differ in their chain length (number of carbons):
- short chain fatty acids (SCFAs): < or equal to C6
- MCFAs: C8 or C10
- LCFAs: > or equal to C12
65
Fatty acids differ in the number and location of double bonds:
- saturated fatty acids (SFAs): no double bonds
- monounsaturated fatty acids (MUFAs): 1 double bond
- polyunsaturated fatty acids (PUFAs): > or equal to 2 double bonds (n-3 and n-6)
66
Trans fatty acids:
unsaturated fatty acids that contain at least one double bond in the trans configuration (opposite sides)
67
Naturally occurring trans fatty acids:
produced in the gut of some animals and foods made from these animals (eg. milk and meat products)
68
Artificial trans fatty acids:
created in an industrial process that adds hydrogen to liquid vegetable oils to make them more solid
69
Fatty acids containing a trans double bond have....
- decrease mobility
- reduced fluidity
- hardening of fat
70
Why are trans fatty acids/fats so popular?
- easy to use
- inexpensive to produce
- last a long time
- give foods a desirable taste and texture
71
Consumption of trans fats increases the risk of coronary heart disease by....
raising levels of bad LDL cholesterol and lowering levels of good HDL cholesterol
72
Cholesterol:
lipid found in the cell membranes of all animal tissues
73
Cholesterol is transported in the ____ _____.
blood plasma
74
Cholesterol is considered a sterol, meaning it is a combination of ....
- steroid
| - alcohol
75
Cholesterol is required to ....
build and maintain cell membranes
76
Cholesterol regulates ____ _____ over a wide range of ______.
- membrane fluidity
| - temperatures
77
Cholesterol is important to maintain ______.
homeostasis
78
Functions of cholesterol:
- aids in the manufacture of bile
- is important for the metabolism of fat soluble vitamins
- is the major precursor for the synthesis of vitamin D and various steroid hormones
79
Bile:
- stored in the gallbladder
| - helps digest fats
80
Lipids are an important ____ ____, especially during prolonged exercise.
energy source
81
Large amounts of ____ can be stored in the body.
fat
82
Fat is stored mainly in _____ _____ _____ from which it is mobilized and transported to the organ that uses it.
subcutaneous adipose tissue
83
Skeletal muscle contains a directly accessible store of fat called....
intramuscular triacylglycerol
84
Lipids have many important functions:
- fuel most cells, important fuels for the contracting muscle
- protects vital organs
- intake of fat soluble vitamins A,D,E and K and carotenoids depends on daily fat intake
- provide the transport medium in the body
- makes food more tasty and attractive
85
How does fat protect vital organs?
a layer of adipose tissue covers these organs to protect them against trauma
86
Only some of the lipid forms can be used as a fuel. Oxidizable lipid fuels include:
- fatty acids
- intramuscular triacylglycerols
- circulating plasma triacylglycerols
87
The regulation of fatty acid oxidation is closely linked to ______ _____.
carbohydrate status
88
When CHO levels are low, to obtain energy from fat.....
- triglycerides must first be broken down by hydrolysis into glycerol and fatty acids
- process is called lipolysis
89
Lipolysis happens in the _____.
cytoplasm
90
In the mitochondrion, the resulting fatty acids are oxidized by _______ into ____ ____, which is used by the _____ cycle.
- beta-oxidation
- acetyl CoA
- Krebs
91
Fatty acids --> (beta oxidation) ____ ____ --> (Krebs cycle) ____
- acetyl CoA
| - energy
92
The _____ that is released from triglycerides after lipolysis directly enters ____ ____.
- glycerol
| - glycolysis pathway
93
If excessive acetyl CoA is created from the oxidation of fatty acids and the _____ _____ is overloaded and cannot handle it, the acetyl CoA is diverted to create _____ _____.
- Krebs cycle
| - ketone bodies
94
3 ketone bodies:
- beta-hydroxybutyrate
- acetoacetate
- acetone
95
When glucose levels are plentiful, the excess acetyl CoA generated by glycolysis can be converted into ____ and subsequently _____. This process, called ______ creates _____ from the acetyl CoA.
- fatty acids
- triglycerides
- lipogenesis
- lipids
96
Lipogenesis takes place where?
in the cytoplasm of adipocytes and hepatocytes
97
Each amino acid consists of a _____ atom bound to 4 chemical groups:
- carbon
- a hydrogen atom
- an amino group, which contains nitrogen
- a carboxylic acid group
- a side chain, which varies in length and structure (different side chains give different properties to the amino acid)
98
Of the ____ amino acids normally found in dietary protein, humans can synthesize ____.
- 20
| - 11
99
The amino acids that can be synthesized =
nonessential AA
100
The AA that cannot be synthesized and must be derived from the diet =
essential AA
101
AA have central roles in the _____ of many organs and tissues.
metabolism
102
AA --> precursors for the synthesis of ____ ____ + precursors and regulators of the synthesis of important _____ _____ and compounds with a ____ ____ ____.
- body proteins
- metabolic mediators
- regulatory biological activity
103
Ex. of AA:
- neurotransmitters
- hormones
- DNA
- RNA
104
Proteins provide _____ to all cells in the human body
structure
105
Proteins are a integral part of the ...
- cell membrane
- cytoplasm
- organelles
106
Many proteins are ____ that increase the rate of metabolic reactions.
enzymes
107
____, _____, and _____ are composed largely of proteins.
- muscle
- skin
- hair
108
____ and _____ are composed of minerals embedded in a protein framework.
- bones
| - teeth
109
When a diet is deficient in protein, structures break down, resulting in:
- reduced muscle mass
- loss of skin elasticity
- thinning hair
110
Muscle is mostly _____. _____ is a good source of protein.
- muscle
| - meat
111
Most common sources of protein:
- meat
| - fish
112
_____ could be at risk for marginal protein intake, and often compensate by eating more _____ and ____.
- vegetarians
- grains
- legumes
113
Grains and legumes do not contain all essential AA:
- grains: lack lysine
- legumes: lack methionine
- exception: well processed soybean protein
114
____ of a protein relates to the degree to which that protein contributes to daily requirements.
quality
115
Most recent method to measure the protein quality of food:
protein digestibility corrected AA score (PDCAAS)
116
PDCAAS evaluates protein quality based on the ____ requirements of humans.
AA
117
PDCAAS: Protein quality rankings are determined by comparing the ____ ____ ____ of a specific food protein against a ____ ____ ____ ____. Maximum score = _____.
- amino acid profile
- standard amino acid profile
- 1.0
118
Score of 1.0 in PDCAAS means...
after digestion of the protein, it provides, per unit of protein, 100% or more of the indispensable AA required
119
_____ and ____ of protein are important.
- amount
| - quality
120
High quality protein:
contains all the essential AAs (9)
121
Incomplete or low quality protein:
protein that is deficient in one or more AA (unable to support human life and growth)
122
____ protein is generally of higher quality than ____ protein. Why?
- animal
- plant
- all essential AA are present
- in larger quantities and in proper proportions
123
An appropriate selection of _____ _____ sources can provide an adequate supply of ____, but consumption of ____ _____ is more likely to ensure a balanced intake.
- plant protein
- AA
- animal protein
124
Protein from different sources that balances the AA intake is called.....
complimentary protein
125
By combining plant foods such as ____ and ____, it is possible to obtain a balanced intake of AA.
- rice
| - beans
126
Ingested AA are transported into the ____ for dispersal to the ____ and _____ throughout the body to be used to create new proteins.
- bloodstream
- liver
- cells
127
If AA exist in excess, the body has no capacity or mechanism for storage; thus they are converted into ____ or ____, or they are _____.
- glucose
- ketones
- decomposed
128
AA decomposition results in _____ an ____ waste.
- hydrocarbons
| - nitrogenous
129
The _____ waste that is liberated in AA decomposition is converted to ____ in the ____ cycle and eliminated in the ____.
- nitrogen
- urea
- urea
- urine
130
AA can also be used as a source of _____ especially in times of starvation.
energy
131
Processing of AA results in the creation of metabolic intermediates, including:
- pyruvate
- acetyl CoA
- acetoacyl CoA
- oxaloacetate
- -a- ketoglutarate
132
AA can serve as a source of energy production through the ____ ____.
Krebs cycle
