In photosynthesis, the plant uses energy from the sun, plus water and carbon dioxide, to synthesize _____.
What term is specific to reactions in which simple compounds are combined into more complex molecules?
Three functions of the liver.
synthesis of urea, synthesis of glycogen, and conversion of fructose to glucose
what is the approximate percent efficiency of conversion of food energy to ATP energy in the body?
the hydrolysis of ATP that often occurs simultaneously with the synthesis of many compounds is an example of what?
what metabolic reaction occurs when a cell uses energy?
ATP releases a phosphate group and become ADP.
what is the series of reactions involving the conversion of glucose to pyruvate known as?
what are some aspects of glycolysis?
it generates ATP, it occurs in the absence of oxygen, and it generates two molecules of pyruvate for each molecule of glucose
what is the sequence of events in the complete oxidation of glucose?
glycolysis -> TCA cycle -> electron transport chain
what is a feature of aerobic metabolism?
energy is produced more slowly than in anaerobic metabolism
the rapid breakdown of glucose in muscles produces large amounts of pyruvate, which leads to a fall in pH within the muscle and that the muscle responds by converting excess pyruvate to what?
what is the response of the muscles when a person is performing intense physical exercise and begins to feel fatigued?
to synthesize more lactate
production of excessive amounts of acetyl CoA molecules lead to the synthesis of ______.
what dietary components can be used to synthesize and store glycogen?
lactose, wheat starch, and plant protein
what is the immediate consequence of a cellular deficiency of oxaloacetate?
the slowing of the TCA cycle
after digestion and absorption, an amino acid not used to build protein will be first subjected to ______.
removal of its amino group
When energy-yielding nutrients are consumed in excess, what can lead to storage of fat?
fat, carbohydrates, and protein
If the carbohydrate content of the diet is insufficient to meet the body's needs for glucose, what can be converted to glucose?
When protein consumption is in excess of body needs and energy needs are met, the excess amino acids are metabolized and the energy in the molecules is _______.
stored as glycogen and fat
In addition to energy, what are the principal end products of cellular oxidation of carbohydrates?
Water and carbon dioxide
what products are generated via the TCA cycle or electron transport chain?
water, energy, and carbon dioxide
Which of the following accounts for the higher energy density of a fatty acid compared with the other energy-yielding nutrients?
a. Fatty acids have a lower percentage of hydrogen-carbon bonds
b. Fatty acids have a greater percentage of hydrogen-carbon bonds
c. Other energy-yielding nutrients have a lower percentage of oxygen-carbon bonds
d. Other energy-yielding nutrients undergo fewer metabolic reactions, thereby lowering the energy yield
b. Fatty acids have a greater percentage of hydrogen-carbon bonds
The number of ATP molecules that can be produced from a molecule of protein, fat, or carbohydrate is generally related to the number of atoms of what?
Approximately how many molecules of ATP are generated from the complete oxidation of one molecule of glucose?
what is the most likely explanation for the body's higher metabolic efficiency of converting a molecule of corn oil into stored fat compared with a molecule of sucrose?
There are fewer metabolic reactions for disassembling the corn oil and re-assembling the parts into a triglyceride for uptake by the fat cells
. Approximately how many ATP molecules are synthesized from the complete oxidation of a molecule of palmitic acid?
If a person consumes 100 kcalories in excess of energy needs from table sugar, approximately how many of the kcalories are stored in the body?
If a person consumes 100 kcalories in excess of energy needs from olive oil, approximately what percentage of the kcalories are stored in the body?
what is a characteristic of the metabolism of specific macronutrients?
The rate of fat oxidation does not change when fat is eaten in excess
How does excess carbohydrate intake contribute to obesity?
It spares oxidation of body fat and dietary fat
what is the body's first response to the absorption of abundant amounts of carbohydrate?
Synthesis and storage of glycogen
what are some features of the metabolism of surplus dietary carbohydrate in human beings?
excess glucose suppresses fat oxidation, excess glucose is first used to fill glycogen reserves, and conversion of excess glucose to fat occurs only to a very limited extent.
Of the total amount of carbohydrate energy consumed by the body, approximately what percentage is used by the brain and nerve cells?
If a normal person expends 1200 kcalories while at rest, approximately how many are used by the brain?
During the first few days of a fast, what energy source provides about 90% of the glucose needed to fuel the body?
what dietary nutrients would most rapidly reverse a state of ketosis in a starving person?
How soon would death occur from starvation if the body was unable to shift to a state of ketosis?
within 3 weeks
what is used to supply some of the fuel needed by the brain only after the body has been fasting for a while?
Elizabeth has been fasting for 4 days in observance of her religious beliefs. You note that her breath smells "fruity." This is most likely due to what?
her body's shift to a state of ketosis
what are some general features of starvation in people
a decrease in metabolic rate, a decrease in immune function, and a decrease in body temperature.
what are some adverse side effects of typical low-carbohydrate diets?
fatigue, nausea, and constipation
Lillie has been losing weight by following a very-low-carbohydrate diet for 2 months. Her primary care physician just diagnosed ketosis through a urine sample. Which of the following symptoms would be another way the physician might have suspected ketosis in Lillie?
Fruity odor on breath
The health benefits of moderate alcohol intake occur in people with a starting age (years) of ____.
what is a definition of a moderate level of alcohol intake per day for the average-sized woman?
up to 1 drink
what is a definition of a moderate level of alcohol intake per day for the average-sized man?
up to 2 drinks
One average-sized can of beer contains about the same amount of alcohol as what?
1½ ounces of vodka.
what is one explanation for the generally lower tolerance for alcohol in women in comparison to men?
Women have lower amounts of stomach alcohol dehydrogenase
what plays a major role in regulating the elimination of alcohol from the body?
liver alcohol dehydrogenase
what are some characteristics of alcohol metabolism?
There are gender differences in the rate of breakdown, The average person needs about two hours to metabolize two drinks, and The amount of alcohol in the breath is proportional to the amount in the blood
Your middle-aged aunt says that she always feels more "tipsy" than her same-size husband, even though their alcohol intake is the same. You respond by saying to your aunt _____.
"Women have less stomach alcohol dehydrogenase enzyme and consequently absorb more of the alcohol into the bloodstream."
In the average healthy person, about how much time is required by the liver to process the alcohol in a typical drink?
What is the sequence of stages that brings about advanced liver disease caused by chronic alcohol toxicity?
Fat accumulation, fibrosis, cirrhosis
What minimum concentration of blood alcohol leads to impaired judgment and increased heart rate?
The Wernicke-Korsakoff syndrome in people with chronic alcohol abuse stems primarily from a deficiency of _____.
chronic excess alcohol intake leads to what effects?
the liver releases more folate into the blood, the kidneys excrete more folate via the urine, and the small intestine absorbs less folate from the diet.
Approximately how many kcalories from ethanol are contained in one standard drink of vodka or rum?