exam 3 Flashcards
1
Q
Where does lipid digestion begin?
A
Lipid digestion begins in the mouth and stomach.
2
Q
What enzymes help with lipid digestion in the mouth and stomach?
A
Lingual lipase and gastric lipase help with lipid digestion in the mouth and stomach.
3
Q
Where are most triglycerides digested?
A
Most triglycerides are digested in the small intestine.
4
Q
What substances help with triglyceride digestion in the small intestine?
A
Bile and pancreatic lipase help with triglyceride digestion in the small intestine.
5
Q
How are digested lipids transported from the lumen of the GI tract into enterocytes?
A
Micelles transport digested lipids from the lumen of the GI tract into the enterocytes.
6
Q
How are short- and medium-chain fatty acids absorbed?
A
Directly into the bloodstream.
7
Q
How are longer-chain fatty acids and other remnants of fat digestion transported?
A
Longer-chain fatty acids and other remnants of fat digestion are packaged into chylomicrons, which transport them through the lymphatic system until they enter the bloodstream.
8
Q
What do lipoproteins transport?
A
Lipoproteins transport triglycerides, cholesterol, and other lipids through the lymph and bloodstream.
9
Q
What is the function of LDLs?
A
LDLs deposit cholesterol in artery walls.
10
Q
What is the function of HDLs?
A
HDLs remove cholesterol from arteries and deliver it to the liver, which uses it in the synthesis of bile and other compounds.
11
Q
What is the function of stored triglycerides in the body?
A
Stored triglycerides cushion and protect bones, organs, and nerves and help maintain body temperature.
12
Q
What is the role of dietary fat in the body?
A
Dietary fat provides essential fatty acids and is needed for the absorption of fat-soluble vitamins and carotenoids.
13
Q
What are eicosanoids, and how are they synthesized?
A
Eicosanoids are substances that regulate several body functions. Essential fatty acids are precursors to arachidonic acid and EPA, which are used to synthesize eicosanoids.
14
Q
What is the function of cholesterol in the body?
A
Cholesterol is used to make sex hormones, bile, and vitamin D.
15
Q
What are phospholipids and cholesterol, and where are they found in the body?
A
Phospholipids and cholesterol are part of cell membranes.
16
Q
Why are dietary lipids, particularly essential fatty acids, important for a healthy diet?
A
Dietary lipids, particularly essential fatty acids, are important for a healthy diet because they provide key nutrients.
17
Q
What types of fats should be limited in the diet?
A
Saturated fats, trans fats, and cholesterol should be limited in the diet.
18
Q
What should the range of dietary fat intake be as a percentage of total kilocalories?
A
The range of dietary fat intake should be from 20 to 35 percent of total kilocalories.
19
Q
How much of total daily kilocalories should come from linoleic acid to meet essential fatty acid needs?
A
5-10 percent of total daily kilocalories should come from linoleic acid to meet essential fatty acid needs.
20
Q
How much of total daily kilocalories should come from alpha-linolenic acid to meet essential fatty acid needs?
A
0.6-1.2 percent of total daily kilocalories should come from alpha-linolenic acid to meet essential fatty acid needs.
21
Q
What is the recommended limit for dietary intake of saturated fat?
A
The recommended limit for dietary intake of saturated fat is no more than 10 percent of total fat consumption
22
Q
How much of fat consumption should be from trans fats?
A
Less than 1 percent of fat consumption should be from trans fats.
23
Q
Are dietary cholesterol and phospholipids essential nutrients?
A
No, dietary cholesterol and phospholipids are not essential nutrients, as they are both made in the body.
24
Q
What are the best food sources to obtain essential fatty acids and limit saturated and trans fats?
A
Lean meat and poultry, fish, low-fat or nonfat dairy products, and limited amounts of nuts and cheese are the best food sources to obtain essential fatty acids and limit saturated and trans fats.
25
Why should commercially prepared baked goods and snack items be consumed rarely?
Commercially prepared baked goods and snack items are high in kilocalories, saturated fat, and trans fats, and should be consumed rarely.
26
What should be used in place of butter?
Vegetable oils should be used in place of butter.
27
Where are trans fats found, and how are they labeled on food products?
Trans fats are found in commercially prepared foods made with partially hydrogenated oils (PHOs). Any trans fats in a food must be listed on the Nutrition Facts panel.
28
Has the FDA banned partially hydrogenated oils (PHOs) from processed foods?
Yes, the FDA has banned all PHOs from processed foods by July 2018.
29
Where is cholesterol found in the diet?
Cholesterol is found mostly in animal-based foods.
30
What do plant-based foods mostly contain in place of cholesterol?
Plant-based foods contain mostly phytosterols in place of cholesterol.
31
What are fat substitutes, and what are they made of?
Fat substitutes can be carbohydrate-based, protein-based, or fat-based
32
Do reduced-fat or fat-free foods still contain kilocalories?
Yes, reduced-fat or fat-free foods still contain kilocalories and should be eaten in limited amounts.
33
What is the primary cause of heart disease?
Heart disease is primarily caused by atherosclerosis, a narrowing of the arteries due to a buildup of plaque.
34
What are some uncontrollable risk factors for heart disease?
Uncontrollable risk factors for heart disease include age, gender, and genetics
35
What are some controllable risk factors for heart disease?
Controllable risk factors for heart disease include high LDL blood cholesterol, low HDL blood cholesterol, high blood pressure, excess body weight, inactivity, type 2 diabetes, and smoking
36
What dietary choices are associated with a reduction in the risk of heart disease?
Limiting saturated fat, cholesterol, and trans fat, increasing fish consumption, and consuming antioxidant-rich fruits, vegetables, whole grains, and nuts are dietary choices associated with a reduction in the risk of heart disease.
37
Can drinking a moderate amount of alcohol help reduce the risk of heart disease?
Yes, drinking a moderate amount of alcohol may help reduce the risk of heart disease in middle-aged and older adults
38
What can regular exercise and maintaining a healthy body weight help with in regards to heart disease?
Regular exercise and maintaining a healthy body weight can help lower LDL cholesterol concentrations and raise HDL cholesterol concentrations.
39
What should you do if you currently smoke?
If you currently smoke, you should quit because smoking damages the walls of the arteries.
40
What are proteins made of?
Proteins are made of chains of amino acids linked together with peptide bonds.
41
What are amino acids composed of?
Amino acids are composed of a central carbon with a carboxyl group, a hydrogen, a nitrogen-containing amine group, and a unique side chain.
42
How many different side chains are there and how many amino acids?
There are 20 different side chains and therefore 20 unique amino acids.
43
What determines the function of a protein?
The precise three-dimensional shape that the protein folds into determines its function.
44
What can denature a protein and alter its shape and function?
Heat, mechanical agitation, acids, bases, and salts can denature a protein and alter its shape and function.
45
Where does chemical digestion of protein begin?
Chemical digestion of protein begins in the stomach.
46
What stimulates the release of HCl and pepsinogen in the stomach during protein digestion?
Gastrin stimulates the release of HCl from the parietal cells and the inactive enzyme pepsinogen from the chief cells during protein digestion.
47
How does HCl contribute to protein digestion in the stomach?
HCl denatures the protein and converts pepsinogen to pepsin, which breaks polypeptides into shorter chains.
48
What hormone stimulates the release of pancreatic proteases during protein digestion?
Cholecystokinin from the duodenum stimulates the release of trypsinogen, carboxypeptidase, and chymotrypsinogen from the pancreas during protein digestion.
49
What do proteases do during protein digestion?
Proteases hydrolyze the shorter protein chains into tripeptides and dipeptides.
50
How are tripeptides and dipeptides further hydrolyzed during protein digestion?
Dipeptidases and tripeptidases hydrolyze the tripeptides and dipeptides into single amino acids.
51
How are absorbed amino acids used in the body?
Absorbed amino acids are used to synthesize new proteins or are converted to nonessential amino acids, ATP, glucose, or fat.
52
How are proteins broken down during digestion?
Proteins are broken down into amino acids with the help of gastric juices, enzymes in the stomach and small intestine, and enzymes from the pancreas and small intestinal lining.
53
What are amino acid pools?
Amino acid pools are a limited supply of amino acids that act as a reservoir for protein synthesis.
54
What happens to surplus amino acids in the body?
Surplus amino acids are deaminated, with the carbon-containing remnants used for glucose or energy or stored as fat, depending on the body's needs.
55
What happens to the nitrogen in amine groups during deamination?
The nitrogen in amine groups is eventually converted to the waste product urea and excreted in urine.
56
How are nonessential amino acids synthesized?
Nonessential amino acids are synthesized through transamination.
57
What do proteins provide in the body?
Proteins provide structural and mechanical support in the body.
58
What is the most abundant protein in the body?
Collagen is the most abundant protein in the body.
59
Where is collagen found in the body?
Collagen is found in all connective tissues, including bones, tendons, and ligaments.
60
What is the function of collagen in the body?
Collagen provides support and elasticity to connective tissues and forms scar tissue to repair injuries.
61
What proteins enable movement in the body?
Actin and myosin enable movement in the body by contracting muscle fibers.
62
What is the role of actin and myosin in nonmuscle movement?
Actin and myosin are also involved in nonmuscle movement, such as during mitosis or when chemicals are transported in the cell cytoplasm.
63
What are enzymes?
Enzymes are biological catalysts that speed up reactions.
64
What are most enzymes made of?
Most enzymes are made of proteins.
65
Why may some enzymes need to be activated?
Some enzymes may need a coenzyme, such as a vitamin, to be activated.
66
Why are enzymes important in the body?
Enzymes are important because they speed up reactions in the body that would occur too slowly otherwise.
67
What is the predominant substance in the human body and how is it distributed within and outside of cells?
The predominant substance in the human body is water, which is distributed both inside (intracellular) and outside (extracellular) of cells.
68
Can proteins move across cell membranes? If not, where do they remain?
Proteins are too large to move across cell membranes and thus remain either within the cells or outside in the extracellular fluid.
69
What is the role of albumin in maintaining fluid balance in the body?
Albumin and other blood proteins play an important role in keeping body fluids dispersed evenly inside and outside of cells, helping to maintain a state of fluid balance. As fluid is forced out of the blood with each heartbeat, the concentration of albumin increases, drawing the fluid from the interstitial spaces back into the blood by osmosis.
70
What happens to the interstitial spaces between cells when fewer proteins are available to draw fluid back into the bloodstream?
When fewer proteins are available to draw the fluid from between the cells back into the bloodstream, a fluid imbalance results. The interstitial spaces between the cells become bloated and the body tissue swells, a condition known as edema.
71
How can proteins alter the pH of the body fluids? What is the normal pH of the blood?
Proteins can alter the pH of the body fluids. The normal pH of the blood is about 7.4. A blood pH below 7.35, a condition called acidosis, can result in a coma. A condition in which the blood pH is too high due to a low concentration of hydrogen ions, known as alkalosis, can cause convulsions.
72
What is an allergen?
An allergen is a nonthreatening substance, typically a protein, that is incorrectly perceived as harmful by the body and triggers an immune response.
73
Which food proteins commonly act as allergens?
Proteins in certain foods, such as peanuts, wheat, and eggs, commonly act as allergens.
74
How can proteins be used as an energy source?
After amino acids are deaminated, the remaining carbon remnants can enter the energy cycle to produce ATP, making proteins a potential energy source.
75
What happens when an individual eats too few kilocalories or carbohydrates?
When an individual eats too few kilocalories or carbohydrates, the stores of glycogen in the liver and muscle become depleted and blood glucose levels drop. The body then turns to specific amino acids called glucogenic amino acids to convert them to glucose through gluconeogenesis in order to raise blood glucose levels.
76
What is an important reason why individuals should not use protein as a regular source of fuel?
Using protein as a regular source of fuel can prevent it from being used for its more important roles in the body.
77
What does it mean for a healthy body to be in nitrogen balance?
When protein intake equals the amount of nitrogen excreted.
78
What is the recommended protein intake for adults according to nitrogen balance studies?
Adults should consume 0.8 gram of protein for each kilogram of body weight, and 10-35 percent of their daily energy intake as protein.
79
Do men and women in the United States typically consume more or less protein than they need?
Men typically consume more than 100 grams of protein daily and women more than 70 grams—in both cases, far more than is needed.
80
What is the AMDR for protein in the United States?
About 15 percent, which is within the recommended range.
81
Do athletes have higher or lower protein needs than nonathletes?
Athletes have higher protein needs than nonathletes.
82
What determines protein quality?
Protein quality is determined by the digestibility of protein and the amino acid profile.
83
Which type of protein is more digestible: animal or plant?
Animal protein is more digestible than plant protein.
84
What is complete protein?
Complete protein is protein that provides a complete set of essential amino acids and some nonessential amino acids.
85
Which foods are sources of complete protein?
Complete protein is found in animal foods, quinoa, and soy.
86
How can the protein quality of incomplete plant proteins be improved?
The protein quality of incomplete plant proteins can be improved by complementing them with protein from other plant sources or animal food sources
87
What are some healthy foods that are rich in protein?
Low-fat dairy, eggs, lean meat, fish, poultry, and meat alternatives such as dried beans, peanut butter, nuts, and soy are healthy foods rich in protein.
88
What are some risks associated with consuming too many protein-rich foods?
Consuming too many protein-rich foods can displace whole grains, fruits, and vegetables, which have been shown to help reduce many chronic diseases. A high-protein diet may increase the risk of heart disease, kidney problems, and calcium loss from bone. Consuming too much protein from animal sources can increase the amount of saturated fat in the diet.
89
What are some healthy foods rich in protein?
Low-fat dairy, eggs, lean meat, fish, poultry, and meat alternatives such as dried beans, peanut butter, nuts, and soy are healthy foods rich in protein.
90
What is protein quality determined by?
Protein quality is determined by the digestibility of protein and the amino acid profile, which includes the types and amounts of amino acids it contains.
91
What is kwashiorkor?
Kwashiorkor is a severe deficiency of protein.
92
What is marasmus?
Marasmus is a severe deficiency of kilocalories.
93
What are some negative effects of consuming too much protein from animal sources?
Consuming too much protein from animal sources can increase the amount of saturated fat in the diet.
94
Why is it important to consume enough protein daily?
It is important to consume enough protein daily to meet the body's needs and prevent protein from being used as energy.
95
What is PEM?
PEM, or protein-energy malnutrition, is caused by an inadequate amount of protein, kilocalories, or both in the diet.
96
What are some types of vegetarians?
Some vegetarians abstain from all animal foods, whereas others may eat eggs and dairy products or even fish or poultry in limited amounts.
97
What are some health benefits of a balanced vegetarian diet?
A balanced vegetarian diet may reduce the risk of heart disease, high blood pressure, diabetes, cancer, stroke, and obesity.
98
What nutrient needs should vegetarians be careful to meet?
All vegetarians must take care in planning a varied diet that meets their nutrient needs, especially for protein, iron, zinc, calcium, vitamin A, vitamin D, vitamin and omega-3 fatty acids.
99
What is ethanol?
Ethanol is the type of alcohol consumed in alcoholic beverages.
100
How is ethanol produced?
Ethanol is produced by the fermentation of sugars by yeast.
101
What are some examples of alcoholic beverages and their sources?
Wine is made from fruits; beer from malted cereals; and distilled spirits from potatoes, grains, molasses, or other ingredients that, following fermentation, yield liquids that undergo distillation.
102
Does alcohol provide nutritional value?
No, alcohol provides kilocalories but very little nutritional value. It is not a nutrient because your body doesn't need it to survive.
103
Why do people drink alcohol?
People drink alcohol to relax, celebrate, socialize, and to feel more "adult."
104
What is considered moderate alcohol consumption according to the Dietary Guidelines for Americans?
Up to one drink a day for women and two drinks a day for men is considered moderate alcohol consumption according to the Dietary Guidelines for Americans.
105
What is a standard drink?
One standard drink contains ½ ounce of alcohol, the amount in a typical 12-ounce bottle of beer, a shot of liquor, or a 5-ounce glass of wine.
106
What is binge drinking?
Drinking excessive amounts of alcohol in a short time is binge drinking.
107
How is alcohol absorbed in the body?
Alcohol is absorbed in the stomach and small intestine.
108
What is the role of alcohol dehydrogenase in metabolizing alcohol?
Alcohol dehydrogenase is an enzyme that metabolizes alcohol in the stomach and liver.
109
What is the initial pathway for alcohol metabolism in the liver?
The initial pathway for alcohol metabolism in the liver is controlled by alcohol dehydrogenase
110
What is the MEOS system and when does it kick into play?
The MEOS system is another enzyme system that kicks into play when too much alcohol is consumed and overwhelms alcohol dehydrogenase.
111
What is blood alcohol concentration?
Blood alcohol concentration is the amount of alcohol in the blood expressed as a percentage.
112
What factors affect the rate of alcohol absorption and metabolism in the body?
A person's gender, genetics, ethnicity, and the amount of food and alcohol consumed affect the rate of absorption and metabolism in the body.
113
What is alcohol poisoning?
Alcohol poisoning is a serious condition that can be fatal, caused by excessive drinking.
114
What should be done if someone has passed out after drinking and cannot be roused?
Someone who has passed out after drinking and cannot be roused requires immediate medical attention.
115
What are some negative effects of alcohol consumption?
Excessive drinking can cause alcohol poisoning, unintentional injuries, disrupt your sleep, and cause hangovers.
116
What are congeners?
Congeners are thought to contribute to hangover symptoms.
117
Is there a cure for a hangover?
The only cure for a hangover is time.
118
What are the long-term consequences of chronic excessive alcohol consumption?
damage to the digestive organs, heart, and liver; malnutrition and weight gain; hormone imbalances; increased risk of cancer and heart disease, depression, and irreversible damage to a developing fetus during pregnancy. Individuals with alcoholic liver disease can experience a fatty liver and deterioration of the liver that develops into alcohol-related hepatitis and cirrhosis.
119
What is alcoholic liver disease?
Alcoholic liver disease is a condition that develops due to excessive alcohol consumption over an extended period. It includes fatty liver, alcohol-related hepatitis, and cirrhosis.
120
What is cirrhosis?
Cirrhosis is a condition in which the liver becomes severely scarred and damaged, leading to impaired liver function. It can be caused by several factors, including chronic excessive alcohol consumption.
121
What is a fatty liver?
A fatty liver is a condition in which fat accumulates in liver cells. It can be caused by several factors, including chronic excessive alcohol consumption.
122
What are the risks associated with excessive alcohol consumption during pregnancy?
Excessive alcohol consumption during pregnancy can lead to irreversible damage to a developing fetus, resulting in fetal alcohol syndrome (FAS) or other fetal alcohol spectrum disorders (FASDs).
123
What is alcohol use disorder (AUD)?
Alcohol use disorder (AUD) is a medical condition characterized by problem drinking that has become severe.
124
What are the two forms of AUD?
The two forms of AUD are alcohol abuse and alcoholism.
125
What are binge drinking and underage drinking?
Binge drinking and underage drinking are forms of alcohol abuse common on college campuses.
126
What is alcoholism?
Alcoholism is a disease characterized by cravings, tolerance, lack of control, and withdrawal symptoms.
127
Can alcoholism be cured?
No, alcoholism cannot be cured, but it can be treated with medical help and psychological support.
128
What is the treatment for alcoholism?
People with alcoholism typically need to abstain from drinking alcohol entirely.
129
What is metabolism?
The sum of all chemical reactions in the body.
130
What is anabolism and catabolism?
Anabolic reactions generally use or absorb energy to combine simpler molecules into larger, more complex ones. They generally release energy as they break down large molecules into simple structures. The breakdown products of catabolism can be used for energy, recycled, or excreted.
131
How do enzymes and coenzymes help regulate metabolism?
Enzymes and their assistant coenzymes enable the chemical reactions of metabolism to occur at fast enough rates to maintain normal body function.
132
How do hormones help regulate metabolism?
When the endocrine system detects a change in the concentration of nutrients, such as when blood glucose levels rise, hormones are released that influence whether enzymes that regulate metabolism are activated or deactivated.
133
what is ATP?
The cells main energy source.
134
ATP's three components?
Adenine + ribose + 3 phosphates.
135
What is a creatine phosphate?
PCr is a high-energy compound formed in muscle cells when creatine (a nitrogenous organic acid found in foods and produced in the body) combines with phosphate.
136
aerobic vs anaerobic respiration?
Anaerobic- does not require oxygen, produceATP faster but will supply E for short time, aerobic metabolism produces less ATP per minute than anaerobic metabolism, but it can continue indefinitely.
137
What is the first step of ATP production from carbs?
Step 1: Glycolysis - in cytoplasm, anaerobic
* conversion of glucose (6C) to 2-pyruvate (3C)* use some ATP
* products: some ATP, pyruvate, water, NADH(electron carrier)
138
What is the second step of ATP production from carbs?
Step 2: conversion of pyruvate to acetyl coA
* occurs in the mitochondria* irreversible
* products: carbon dioxide, NADH, and acetyl coA
139
What is the third step of ATP production from carbs?
Step 3: TCA or Kreb's cycle
* occurs in the mitochondria* acetyl coA reacts with oxaloaxetate (from glucose)
* products: major producer of CO2, NADH, FADH(another e carrier) and some ATP
140
What is the fourth step of ATP production from carbs?
Step 4: electron transport chain
* occurs in the mitochondria* NADH and FADH transfers electrons toprotein complexes with oxygen as finalacceptor and producing water
* Products: water and main producer ofATP
* Complexes require iron and vitamins
141
What is the livers role in metabolism?
Fructose and galactose can enter glycolysis and also be use for ATP production.
142
What are the end products of CHO metabolism?
energy ATPs, carbon dioxide CO2, water H2O
143
What is the cori cycle?
A process in the liver that regenerates glucose from lactate released by muscles.
144
What are the end products of lipid metanolism?
Energy ATPs, Carbon dioxide CO2, Water H2O, ketones
145
What are some ketosis symptoms?
early symptoms - Frequent urination, thirst or a very dry mouth, high blood glucose, high level of ketones in urine. Then you will start to experience fatigue, dry skin, confusion and hard time breathing.
146
Metabolism of amino acids?
Must remove the acid group - decarboxylate
Must remove the amino group - deaminate ortransaminate
147
What are the end products of protein metabolism?
Energy ATPs, Carbon dioxide CO2, Water H2O, urea
148
What are the sources of fuel during fed?
dietary carbs source of fuel
anabolic, glycogenesis, lipogenesis,and protein synthesis
149
What are the sources of fuel in-between meals?
Glycogen is the source of fuel, some lipolysis
150
What are the sources of fuel during long term fasting?
lipolysis and protein isbeing broken down
