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113 terms

Nutrition Chapter 7

Metabolism
STUDY
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What is the sum of all chemical reactions that go on in the body?
Metabolism
In photosynthesis, plants use the sun, water and CO2 to synthesize
carbs
"Powerhouses" are
mitochondria
A feature of catabolic reactions is that they
release energy
Reactions where simple compounds are combined into more complex molecules are
Anabolic
The site of lipid synthesis in the cell is the
smooth endoplasmic reticulum
Which is an anabolic reaction: Pyruvate synthesis from glucose, Acetyl CoA synthesis from cholesterol, CO2 from citric acid, or cholesterol from acetyl CoA molecules?
cholesterol from acetyl CoA molecules
The formation of glycogen by the liver is an example of
anabolism
Which reaction is catabolic: Glucose formation from glycerol, urea formation from an amino acid, albumin formation from amino acids, or palmitic acid formation from acetate?
Urea formation from an amino acid
All are functions of the liver except: Synthesis of urea, synthesis of glycogen, production of red blood cells, or conversion of fructose to glucose
production of red blood cells
What is the approximate percent efficiency of conversion of food to ATP energy in the body?
50
In the adult body, food energy not stored as fat or glycogen is lost as
heat
What is a coenzyme?
An organic molecule required for the functioning of an enzyme
The hydrolysis of ATP that often occurs simultaneously with the synthesis of many compounds is an example of
coupled reactions
Which metabolic reaction occurs when a cell uses energy?
ATP releases a phosphate group and becomes ADP
What is the major energy carrier molecule in most cells?
ATP
The basic units derived from food include all except: glycerol, starches, amino acids, fatty acids.
starches
What percent of the body's expenditure is furnished by amino acids?
10-15
What cannot be formed from acetyl CoA molecules?
glucose
Which cannot be formed from pyruvate in humans: Glucose, Fructose, Lactic acid, or Linoleic acid?
Linoleic acid
Glycosis is the conversion of
glycogen to pyruvate
Is glycosis reversible?
yes
What is the order of events in the complete oxidation of glucose?
Glycosis, TCA cycle, electron transport chain
Energy in aerobic metabolism is produced (slower/faster) than energy in anaerobic metabolism
slower
Aerobic reactions require
oxygen
When working out, excess pyruvate is converted to
lactate
The Cori cycle involves the interconversion of
lactate and glucose
Which is not a possible fate for metabolized glucose: Urea, acetyl CoA, amino acids, or muscle glycogen
Urea
Which nutrient can be made from compounds composed of 2 carbon skeletons?
Fatty acids
Which is a possible fate of acetyl CoA: degradation to urea, synthesis to glycerol, synthesis to fatty acids, or degradation to ammonia?
synthesis to fatty acids
What is the first product of fatty acid catabolism?
Acetyl CoA
Fatty acid oxidation results in the direct production of
acetyl CoA
Production of excessive amounts of acetyl CoA molecules leads to the synthesis of
fatty acids only
In a triglyceride that contains 54 carbons, how many of those can become a part of glucose?
3
What compound cannot be formed from fatty acids: Glucose, Ketones, CO2, or Acetyl CoA
Glucose
What % of weight of triglycerides cannot be converted to glucose?
95
How many acetyl CoA molecules can be obtained from oxidation of an 18 carbon fatty acid?
9
What dietary component cannot be used to synthesize and store glycogen?
Animal fats
Which dietary component cannot be used to make body proteins?
fatty acids
An immediate consequence of a cellular deficiency of oxaloacetate is a slowing of
the TCA cycle
All of the following may serve as precursors for oxaloacetate except: fat, starch, glucose, protein
fat
What is the immediate fate of of excess dietary protein in the body
deaminated
After digested and absorbed, an amino acid that is not used to build protein will first be subject to
removal of its amino group
What leads to the production of urea?
Oxidation of amino acids
If carbohydrate content of the diet is insufficient, what is converted to glucose?
amino acids
When protein consumption is excess, excess amino acids are metabolized and the energy in the molecule is stored as
glycogen and fat
What are the products from the complete oxidation of fatty acids?
H20, CO2, and energy
Which is not generated by the TCA cycle or electron transport train: water, CO2, ammonia, or energy?
ammonia
When is oxygen used in the electron transport chain?
at the end
Why do fatty acids have the most energy of all the nutrients?
They have a greater percentage of hydrogen-carbon bonds
The number of ATP molecules produced from carbs, protein, or fat, is related to the number of atoms of
hydrogen
How many molecules of ATP are generated from the complete oxidation of 1 molecule of glucose?
32
How many ATP molecules are synthesized from the complete oxidation of a molecule of palmitic acid?
129
Which of the following can be synthesized from all 3 energy yielding nutrients: Lactate, glycogen, oxaloacetate, or acetyl CoA?
Acetyl CoA
Which nutrient is easiest for the body to convert to fat?
fat
If a person consumes 100 kcals of excess sugar, how many are stored in the body?
75
If 100 kcals of excess olive oil are consumed, what % are stored in the body?
95
Which of the following is a characteristic of the metabolism of specific macronutrients?
a. The rate of fat oxidation does not change when fat is eaten in excess
b. The rate of protein oxidation does not change when protein is eaten in excess
c. The rate of glucose oxidation does not change when carbohydrate is eaten in excess
d. The conversion of dietary glucose to fat represents the major pathway of carbohydrate utilization
Which of the following is a characteristic of the metabolism of specific macronutrients?
a. The rate of fat oxidation does not change when fat is eaten in excess
b. The rate of protein oxidation does not change when protein is eaten in excess
c. The rate of glucose oxidation does not change when carbohydrate is eaten in excess
d. The conversion of dietary glucose to fat represents the major pathway of carbohydrate utilization
the rate of fat oxidation does not change when fat is eaten in excess
How does excess carb intake contribute to obesity?
it spares oxidation of body fat and dietary fat
What is the body's first reaction to the absorption of abundant amounts of carbs?
synthesis and storage of glycogen
All of the following are features of the metabolism of surplus dietary carbohydrate in human beings except
a. excess glucose suppresses fat oxidation.
b. excess glucose is oxidized only very slowly.
c. excess glucose is first used to fill glycogen reserves.
d. conversion of excess glucose to fat occurs only to a very limited extent.
All of the following are features of the metabolism of surplus dietary carbohydrate in human beings except
a. excess glucose suppresses fat oxidation.
b. excess glucose is oxidized only very slowly.
c. excess glucose is first used to fill glycogen reserves.
d. conversion of excess glucose to fat occurs only to a very limited extent.
excess glucose is oxidized only very slowly
Which of the following is a feature of the metabolism of surplus dietary fat?
a. Excess fat is almost all stored
b. Excess fat promotes increased fat oxidation
c. Excess fat spares breakdown of body proteins
d. Conversion of excess fat to storage fat is inefficient
excess fat is almost all stored
After roughly a day of fasting, what is most depleted in the body?
glycogen
Of the total amount of carbs in the body, what percentage is used by the brain and nerve cells?
50
What percent of carbs in the body is used just by the brain?
25
During the first few days of a fast, which energy source provides about 90% of the glucose needed to fuel the body?
protein
What dietary nutrient would most rapidly reverse a state of ketosis in a starving person?
carbohydrates
How soon would you die from starvation if the body was unable to shift to a state of ketosis?
within 3 weeks
Ketosis occurs when
fats are partially oxidized
A person with acetone breath most likely has the condition known as
ketonemia
What does the brain use for fuel after fasting for a while?
ketones
Ketosis makes the breath smell
fruity
Ketosis is defined as an elevation of
ketones in the blood
How are ketones formed?
Condensation of acetyl CoA molecules
Is a decrease in mental alertness a feature in starving people?
no
Does ketosis raise or lower blood ph?
lower
Which is classified as a ketone body: sorbitol, acetyl CoA, pyruvate, or acetoacetate,
acetoacetate
Adverse side effects of typical low carb diets include all except: fatigue, high blood pressure, nausea, or constipation
high blood pressure
What type of diet is associated with ketosis?
low carb
The health benefits of moderate alcohol intake occur in people with a starting age of
35
Binge drinking is the successive consumption of how many drinks?
4-5
How many drinks per day is moderate alcohol intake for an average woman?
up to one
How many drinks per day is moderate alcohol intake for a man?
up to 2
The chemical structure of ethanol consists of
2 carbons and one hydroxyl
The ratio of proof to alcohol percentage is
2:1
The amount of ethanol in a drink is how many ounces?
.5
How many kcals are in 3 ounces of 80 proof rum?
200
A beer contains the same amount of alcohol as how many ounces of vodka?
1.5
Why do women have a lower alcohol tolerance than men?
Women have lower amounts of stomach alcohol dehydrogenase
What organ absorbs alcohol first?
stomach
What organ oxidizes alcohol?
liver
Which nutrient absorbs alcohol best?
carbs
The metabolism of alcohol begins in the
stomach
Which of the following is characteristic of alcohol absorption?
a. It is slowed when the stomach is full of food
b. It is increased when high-fat snacks are eaten
c. It is increased when carbohydrate snacks are eaten
d. It is lower in women than in men of the same body weight
It is slowed when the stomach is full of food
What determines how fast alcohol is eliminated from the body?
Liver alcohol dehydrogenase
What is acetaldehyde?
an intermediate in alcohol metabolism
Excess alcohol intake leads to a reduction in the synthesis rate of
liver glucose
What is the sequence of the stages that brings out advanced liver disease caused by chronic alcohol toxicity?
Fat accumulation, fibrosis, cirrhosis
What is MEOS?
A system of enzymes that oxidizes alcohol and drugs
What percent of alcohol is eliminated through urine and breath
10
Which function is affected first when you start drinking
Judgement and reasoning
What blood alcohol percent defines drunkenness?
.10
What blood alcohol percent leads to impaired judgement and increased heart rate?
.05
what blood alcohol concentration in the body is fatal?
.50
What hormone production is surpressed following alcohol intake?
Antidiuretic hormone production
The Wernicke-Korsakoff syndrome in people with chronic alcohol abuse stems primarily from a deficiency of
thiamin
Ethanol metabolism increases the output of what acid?
gastric acid
Chronic excess alcohol intake leads to all of the following effects on folate except
a. the small intestine recycles more folate.
b. the liver releases more folate into the blood.
c. the kidneys excrete more folate via the urine.
d. the small intestine absorbs less folate from the diet.
The small intestine recycles more folate
how many kcals from ethanol are in 1 drink of vodka or rum?
100
What % of fatal traffic accidents involve alcohol?
40
What is the median weekly number of alcoholic drinks consumed by college students?
1.5
What fraction of domestic violence incident involve alcohol use?
2/3
127. Which of the following is a characteristic of alcohol use?
a. Ingestion of alcohol cools the body
b. Alcohol stimulates the appetite for most people
c. Since alcohol is legal, it is not classified as a drug
d. Intake of alcohol along with raw seafood reduces the chances of contracting hepatitis
Ingestion of alcohol cools the body