1
Q
what is the difference between fat and lipid
A
fat often refers to triglycerides lipid is the chemical term
2
Q
what are four different kinds of lipids
A
fatty acids, triglycerides, phospholipids, and sterols
3
Q
how much energy does fat provide?
A
9 kcal/g
4
Q
people tend to eat more than ____% calories from fat
A
35
5
Q
what type of fat is consumed most?
A
saturated fat
6
Q
saturated fats increases risk of
A
cardiovascular disease
7
Q
where is fat naturally found?
A
in nuts and avocado
8
Q
why do we need fat? (structure and lubrication) (6)
A
- fat under skin and around internal organs 2. defines body shape 3. provide stored energy 4. insulate the body from temp changes 5. insulate nerves 6. padding for internal organs against physical shock
9
Q
why do we need fat? (regulation) (2)
A
- cholesterol consumes or made by the liver used to make sex hormones and stress hormones 2. regulates blood pressure, blood clotting
10
Q
what types of fat are there? (4)
A
- saturated (meat and dairy) 2. monounsaturated (olive oil) 3. polyunsaturated (omega 3 - fish, omega 6 - sunflower seeds and sunflower oil) 4. trans fat (prepackaged foods)
11
Q
what is a fatty acid?
A
-small unit of fat -have a carboxyl acid group at one end and a methyl group -come in different sizes (short medium and long) (the number of carbons and the location of the bonds)
12
Q
short and medium chain fatty acids are ____________ and are __________ fatty acid
A
water- soluble, saturated
13
Q
what is a long chain saturated fatty acid? (4)
A
-greater than 12 carbons -not water-soluble -solid at room temperature -plant source (tropical oils, palm oil, coconut oil)
14
Q
what is a saturated fatty acid? (2)
A
-solid at room temperature -no double bonds
15
Q
what is an unsaturated fatty acid? (3)
A
-liquid at room temp -monounsaturated fats (one double bond) -polyunsaturated fats (more than one double bond)
16
Q
monounsaturates are found in: (3)
A
avocados, nuts, seeds, vegetable oils
17
Q
polyunsaturates are found in: (8)
A
herring, mackerel, salmon, trout, fish oil, nuts, seeds, vegetable oils
18
Q
monounsaturated and polyunsaturated fats are _____ at room temp
A
liquid
19
Q
polyunsaturated fats contain ________ double bond(s)
A
two or more carbon-carbon
20
Q
polyunsaturated fats improve ______ and lowers risk of_______ and _______
A
blood cholesterol levels, heart disease, type 2 diabetes
21
Q
what are essential fatty acids?
A
alpha linolenic acid and linolenic acid -body makes most fatty acids from glucose or other sources of carbon, hydrogen and oxygen or breaks down fat
22
Q
omega 3 fatty acids decrease the risk of _________
A
cardiovascular disease
23
Q
where are omega 3 fatty acids found? (9)
A
fish, walnuts, flaxseed, leafy green vegetables, canola oils, salmon, tuna, mackerel, sardines
24
Q
where are omega 6 fatty acids found? (2)
A
-corn -safflower oil
25
saturated fatty acids are found in ______ and ______ products
animal, dairy
26
saturated fats are found in: (11)
beef, chicken, lamb, pork, coconut, palm oil, butter, cheese, whole milk, lard, shortening
27
trans fats are found in: (3)
margarines, commercially fried foods, bakery products with shortening, margarine, or oils containing hydrogenated oils and fats
28
what do unsaturated fats have to do with trans fats?
-natural unsaturated fatty acids (with a double bond) have a configuration called cis (bent) -what makes it bend is the double bond
29
why was trans fat banned in canada?
increases blood cholesterol levels and risk of heart disease
30
what happens when unsaturated fat with a double bond undergoes hydrogenation?
there is a flip in the chemical bonds which makes unsaturated fatty acid into trans fatty acid
31
what are the three nutrient claims that can be made about trans fat?
-free of trans fat -reduced trans fat -lower trans fats
32
what is a triglyceride?
-looks like the letter E -type of fat found in our bodies -made of short, medium and long chain fatty acids, saturated and unsaturated fatty acids -influences taste, texture, and physical properties
33
what is a monoglyceride and diglycerides?
monoglyceride: 1 fatty acid attached to glycerol diglycerides: 2 fatty acids attached to glycerol
34
What are phospholipids? (5)
-backbone glycerol -2 fatty acids attached + phosphate group -soluble in fat -act as emulsifiers -lipid belayer to help regulate what passes in and out of the cell
35
what is a sterol and where is it produced?
-cholesterol found in animals -made by the liver (not essential for the diet)
36
what is bile?
a bitter green-brown alkaline fluid that helps digestion. its secreted by the liver and stored in the gallbladder
37
where is 90% of cholesterol found?
cell membranes
38
cholesterol is needed to make vitamin _____
D
39
Micelles have a ______ centre surrounded by ______
fat-soluble, bile
40
micelles help absorption of ______ across the _______
lipids, mucosal
41
where does fat digestion occur?
small intestine
42
the way lipids are transported from the small intestine to various parts of the body depends on:
whether or not the fatty acids are water-soluble
43
what is a chylomicron? (3)
-lipoprotein -transports lipids from the mucosal cell of the small intestine and delivers triglycerides to other body cells -transports long-chain fatty acids into the lymphatic system and blood stream
44
what is lipoprotein? (3)
-transports triglycerides, cholesterol and fat-soluble vitamins from the small intestine -also transports stored and newly made lipids -lipoprotein = triglycerides and cholesterol in the middle without an outside layer of protein, phospholipids and cholesterol
45
what happens to chylomicrons in the lymphatic system?
chylomicrons are transferred into the lymphatic system and then enter the blood stream without first passing through the liver
46
what happens to the cholesterol and protein in the chylomicron?
goes to the liver and is disassembled
47
low density lipoprotein (LDL) is considered the ____
bad
48
high density lipoprotein (HDL) is considered ____
good
49
HDL helps prevent heart disease
50
what are steps 1-3 for lipid transport and delivery?
1) small intestine —> micelles —> chylomicrons —> lymph vessel —> blood 2) lipoprotein lipase —> chylomicrons —> triglycerides —> fatty acids and glycerol —> cells 3) chylomicron remnants —> go to the liver and are disassembled
51
what are steps 4-5 for lipid transport and delivery?
4) VLDL transport lipids away from the liver. at the tissues, lipoprotein lipase breaks down triglycerides in the VLDL 5) IDL formed from step 3 which goes to the liver or is transformed in the blood —> LDL particles
52
what are steps 6-7 for lipid transport and delivery?
6) LDL particles bind LDL receptors —> cell 7) HDL pick up cholesterol —> returns to the liver for disposal or take it to organs that have high cholesterol requirements for hormone synthesis
53
what happens when we eat fat?
when energy from fat is ingested in excess of needs, excess is stored in adipose tissue. excess energy consumed as fat can be transported directly from the intestines to the adipose tissue in chylomicrons
54
when blood glucose increases, ______ stimulates glucose to be stored as glycogen
insulin
55
insulin stimulates _______ ______ _______, promotes uptake of __________
enzyme lipoprotein lipase, triglycerides
56
what are the essential fatty acids?
-omega 3 (alpha linolenic acid, ALA) -omega 6 (liolenic acid, LA) -both used to make hormone like molecules called eicosanoids -ALA and LA have opposite effects
57
diets high in saturated fats and high fat diets make cells more ______
cancerous
58
what can you eat / do to lower cholesterol?
soluble fibre, soy protein, plant sterols, reduce intake of saturated fats, exercise
59
plant sterols are naturally found in:
grains, vegetable, fruits, legumes, nuts, seeds, vegetable oil
60
what methods of cooking are good for heart health?
-bake, broil bbq (3 Bs) -roast, steam, microwave -reduce use of butter -avoid deep frying and buying pre-packaged food
61
what does AMDR stand for?
acceptable macronutrient distribution range
62
what is the adequate intake of liolenic acid for men and women?
men - 17 g/d women - 12 g/d
63
how much energy should adults be getting from fat?
20-35%
64
what is protein?
-contains carbon, hydrogen, oxygen, nitrogen -provides 4 kcal/gram -found in food and in the body -amino acid chains
65
what nutrients are found in protein?
animal products - B vitamins, iron, zinc, calcium, saturated fat plant product s- B vitamins, iron, zinc, calcium, fibre, unsaturated fats
66
what % of the human body is protein?
about 15%
67
protein provides us with ______ and _____
1) structure (hair, skin, organs, blood tissue, muscle, tendons, tissue, etc) 2) protection (skin and antibodies)
68
what does protein do in the body? (5)
-transport proteins: hemoglobin in red blood cell picks up oxygen in lungs and transports it to other organs -enzymes: speeds up metabolic reactions -peptide hormones: insulin and glucagon bind to protein receptors on the cell membrane -helps us move -acid base balance:
69
what is an amino acid? (a.a.)
-building block of protein -4 chemical groups: hydrogen, amino group, acid group, and side chain -there are 20 amino acids: 9 essential and 11 nonessential
70
an essential amino acid must be...
consumed in the diet (if we dont, new proteins cannot be made in the body)
71
what do peptide bonds do?
link amino acids together, form protein, and binds the acid group (COOH) to nitrogen group (NH2)
72
how are polypeptides formed?
more than three amino acids bonded together
73
how is a di-peptide bond formed?
it is formed between 2 amino acids
74
How are tripeptides formed?
3 amino acids linked by a peptide bond
75
protein is made up of 1 or more _______ ______
polypeptide chains
76
the _____ of protein determines function
shape
77
what causes change in protein structure?
temperature and pH
78
what is denaturation?
change in protein 3-D structure
79
Define **lipid**.
A group of hydrophobic organic molecules, including fats, oils, and steroids.
80
What is the primary function of **lipids** in the body?
To store energy, provide insulation, and make up cell membranes.
81
True or false: **Phospholipids** are essential for cell membrane structure.
TRUE
## Footnote
Phospholipids form bilayers that create cell membranes, allowing selective permeability.
82
Fill in the blank: **Triglycerides** consist of glycerol and _______.
three fatty acids
83
What are **saturated fats**?
Fats with no double bonds between carbon atoms, solid at room temperature.
84
Define **unsaturated fats**.
Fats containing one or more double bonds, usually liquid at room temperature.
85
What is the role of **bile salts** in digestion?
To emulsify fats, increasing their surface area for digestive enzymes.
86
True or false: **Lipases** are enzymes that break down lipids.
TRUE
## Footnote
They hydrolyze triglycerides into glycerol and fatty acids.
87
What is the **structure** of a phospholipid?
A hydrophilic head and two hydrophobic tails.
88
Fill in the blank: **Cholesterol** is a type of _______.
sterol
89
What is the function of **cholesterol** in cell membranes?
To maintain membrane fluidity and stability.
90
Define **lipid digestion**.
The process of breaking down lipids into fatty acids and glycerol for absorption.
91
What is the **first step** in lipid digestion?
Emulsification by bile salts in the small intestine.
92
True or false: **Micelles** are formed during lipid digestion.
TRUE
## Footnote
Micelles help transport fatty acids and monoglycerides to intestinal cells.
93
Fill in the blank: **Fatty acids** can be classified as _______ or _______.
saturated; unsaturated
94
What is the role of **chylomicrons**?
To transport dietary lipids from the intestines to other locations in the body.
95
Define **lipoproteins**.
Complexes of lipids and proteins that transport lipids in the bloodstream.
96
What are the two main types of **lipoproteins**?
Low-density lipoproteins (LDL) and high-density lipoproteins (HDL).
97
True or false: **LDL** is known as 'bad' cholesterol.
TRUE
## Footnote
High levels of LDL can lead to plaque buildup in arteries.
98
What is the primary source of **energy** from lipids?
Fatty acids are oxidized to produce ATP.
99
Fill in the blank: **Essential fatty acids** must be obtained from _______.
the diet
100
What is the function of **omega-3 fatty acids**?
To support heart health and reduce inflammation.
101
Define **ketosis**.
A metabolic state where the body uses ketones from fat for energy.
102
What triggers **ketosis**?
Low carbohydrate intake or prolonged fasting.
103
True or false: **Trans fats** are healthier than saturated fats.
FALSE
## Footnote
Trans fats are linked to increased heart disease risk.
104
Fill in the blank: **Lipid-soluble vitamins** include vitamins A, D, E, and _______.
K
105
Define **protein**.
A large biomolecule composed of one or more long chains of amino acids.
106
What are the **building blocks** of proteins?
Amino acids are the building blocks of proteins.
107
True or false: Proteins are made up of **nucleotides**.
FALSE
## Footnote
Proteins are made of amino acids, not nucleotides.
108
Fill in the blank: Proteins are synthesized in the **______**.
Ribosome
109
What is the **primary structure** of a protein?
The sequence of amino acids in a polypeptide chain.
110
Define **secondary structure** in proteins.
The local folded structures that form within a protein due to hydrogen bonding.
111
What are **alpha helices** and **beta sheets**?
Common types of secondary structures in proteins.
112
True or false: The **tertiary structure** is the overall 3D shape of a protein.
t
113
What is the role of **disulfide bonds** in proteins?
They stabilize the tertiary structure by linking cysteine residues.
114
Define **quaternary structure**.
The arrangement of multiple polypeptide chains in a protein.
115
Fill in the blank: **Denaturation** of proteins involves _______ their structure.
Unfolding
116
What is **enzyme**?
A protein that acts as a catalyst to speed up biochemical reactions.
117
True or false: Enzymes are consumed in the reactions they catalyze.
FALSE
## Footnote
Enzymes are not consumed; they can be reused.
118
What is **substrate specificity**?
The ability of an enzyme to select and bind to a specific substrate.
119
Define **digestion**.
The process of breaking down food into smaller components for absorption.
120
What are the main organs involved in **protein digestion**?
Stomach and small intestine.
121
Fill in the blank: **Pepsin** is an enzyme that digests _______.
Proteins
122
What is the role of **proteases**?
They break down proteins into smaller peptides and amino acids.
123
True or false: Protein digestion begins in the **mouth**.
FALSE
## Footnote
Protein digestion begins in the stomach.
124
What is the function of **hydrochloric acid** in the stomach?
It activates pepsin and creates an acidic environment for digestion.
125
Define **absorption** in the context of digestion.
The process of taking nutrients from the digestive tract into the bloodstream.
126
What are **amino acids** used for after absorption?
They are used for protein synthesis and other metabolic functions.
127
Fill in the blank: **Complete proteins** contain all _______ amino acids.
Essential
128
What is a **limiting amino acid**?
An essential amino acid that is in the shortest supply in a protein source.
129
True or false: All proteins are made from the same **20 amino acids**.
t
130
What is the significance of **protein folding**?
Proper folding is crucial for protein function and stability.
Nutrition 120
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