Ch 25 Flashcards
Define Metabolism
the sum of all body chemical reactions
Define Catabolism
is breaking down larger molecules into smaller molecules. Catabolic reactions provide more energy than they consume; they are exergonic – they liberate heat
Define Anabolism
is building up smaller molecules into larger molecules. Anabolic reactions consume more energy than they produce; they are endergonic – they consume heat
Metabolism and Nutrition
- Metabolism is an energy-balancing act
- ATP (adenosine triphosphate), is the energy currency unit that participates most often in living cells which couples energy-releasing catabolic reactions to energy-requiring anabolic reactions.
- The exact reactions that occur depend on which enzymes are active in a particular cell at a particular time
- ATP (adenosine triphosphate), is the energy currency unit that participates most often in living cells which couples energy-releasing catabolic reactions to energy-requiring anabolic reactions.
Define nutrient
is a “food or liquid that supplies the body’s metabolic needs. Nutrients include: A necessary chemical (such as Na+ and other minerals) A substance that provides energy (such as lipids or carbohydrates like glucose) Something that helps in growth of new body components (such as vitamins) A substance that repairs or maintains body functions (such as proteins, or amino acids to make proteins)
ATP
ATP temporarily stores and transfers energy given off in catabolic reactions and transfers it to anabolic reactions that require energy.
How Do We Get Energy From ATP?
By breaking the high- energy bonds between the last two phosphates in ATP
Define Oxidation-reduction or redox reactions
- Oxidation – removal of electrons
- Decrease in potential energy
- Dehydrogenation – removal of hydrogens
- Liberated hydrogen transferred by coenzymes
- Nicotinamide adenine dinucleotide (NAD)
- Flavin adenine dinucleotide (FAD)
- Glucose is oxidized
- Reduction – addition of electrons
- Increase in potential energy
REDOX Reactions
- Chemical reactions in which a pair of electrons are exchanged as a means of transferring energy
- Oxidation is the removal of electrons
- Reduction is the addition of electrons
Oxidation Reduction Chemisty: Redox Chemistry
- Oxidation and Reduction reactions always take place simultaneously.
- Loss of electrons – oxidation
- Gain of electrons - reduction
Carbohydrate Metabolism
- Glucose (C6H12O6) is not just an example we happen to choose – it is indeed the body’s preferred source of fuel.
- During digestion, polysaccharides and disaccharides are hydrolyzed into the monosaccharides glucose (80%), fructose, and galactose
- These are absorbed into the villi of the small intestine and carried to the liver
Summary of Cellular Respiration
- In the total oxidation of 1 molecule of glucose, 36-38 molecules of ATPs are generated, depending on the tissue.
- Only 4 ATP are generated by substrate level phosphorylation (directly transferring a high energy phosphate from one organic molecule to another) in glycolysis and the Krebs cycle
- Most of the ATP (either 32 or 34) is made by oxidative phosphorylation using the cytochromes of the electron transport chain and O2 as the final electron acceptor
Summary of Cellular Respiration
- The location of events of cellular respiration are summarized in this graphic
- Glycolysis is occurring in the cytoplasm
- The Krebs cycle takes place in the mitochondrial matrix
- The cytochrome proteins of the electron transport chain are embedded into the inner mitochondrial membrane
Cellular Respiration
Glucose Anabolism
- GLYCOGENESIS - Glucose synthesized to GLYCOGEN
- GLUCONEOGENESIS is the process of forming “new” glucose or its metabolites from fat or protein breakdown
- GLYCOGENOLYSIS is break down of glycogen
Glucose storage - GLYCOGENESIS
- Glucose stored as glycogen: glycogenesis
- Polysaccharide that is the only stored carbohydrate in humans
- Insulin stimulates hepatocytes and skeletal muscle cells to synthesize glycogen
- 75% stored in skeletal muscle, 25% in liver
- Glucose → G6P → G1P → Uridine diphosphate glucose →glycogen
- and release into blood
Glucose release - GLYCOGENOLYSIS
- Glucose release: glycogenolysis
- Glycogen stored in hepatocytes broken down into glucose and release into blood
- HEPATOCYTES: GLYCOGEN → G1P → G6P → GLUCOSE
- MUSCLE: GLYCOGEN → G1P
Glycogenesis and glycogenolysis
Glucose formation - GLUCONEOGENESIS
- No food, low glycogen stores in liver, EAT! OR
- Triglycerides and Protein catabolism
- Lactic acid, glycerol, amino acids converted to Pyruvic acid → glucose formation or Krebs cycle
Making Glucose
- Gluconeogenesis is the process of forming “new” glucose or its metabolites from fat or protein (from non-carbohydrate sources). Gluconeogenesis is always taking place, but it occurs on a large scale during fasting, starving, or eating a low carbohydrate diet
- Lactic acid, amino acids, and the glycerol portion of triglycerides are used to form glucose molecules or pyruvic acid to enter the Krebs cycle
Lipids
- Although the word “fat” is commonly used to mean lipids, fats are, in fact, just one subgroup of lipids called triglycerides
- Other lipids include waxes, sterols (steroid hormones), fat-soluble vitamins (such as vitamins A, D, E and K), monoglycerides, diglycerides, phospholipids, and others
- For metabolic purposes, triglycerides are a condensed form of useable energy
- Other lipids include waxes, sterols (steroid hormones), fat-soluble vitamins (such as vitamins A, D, E and K), monoglycerides, diglycerides, phospholipids, and others
Lipids
- All triglycerides are composed of a glycerol backbone combined with 3 fatty acids
- Fatty acids are anywhere from 4 to 24 carbons long,and they may have all single carbon-carbon bonds (saturated), or some double or triple bonds (making them unsaturated)
Triglycerides
- are nonpolar, and therefore very hydrophobic molecules
- To be transported in watery blood, they must first be made more water-soluble by combining them with carrier molecules called lipoproteins (produced in the liver)
- Lipoproteins vary in their size, density, and the amount of cholesterol and protein in their make-up
- To be transported in watery blood, they must first be made more water-soluble by combining them with carrier molecules called lipoproteins (produced in the liver)
Lipoproteins
- In general, however, all lipoproteins have:
- An outer shell that is made hydrophilic due to polar proteins (plus amphipathic phospholipid and cholesterol)
- An inner core that is hydrophobic - a place where the triglycerides are transported
Lipoproteins – Docking proteins
- APO C-2 (activates lipoprotein lipase)
- APO E (hepatocyte docking protein)
- APO B100 (docking protein for LDL to enter by receptor-mediated endocytosis)
Types of lipoproteins:
- Chylomicrons – transport of ingested lipids to adipose tissue for storage (APO C-2 & APO E)
- Very low-density lipoproteins (VLDL) – endogenous lipids, transport trigs made in liver to adipocytes for storage (APO C-2)
- Low-density lipoproteins (LDL) are used to transport lipids to repair cells throughout. Contain 75% of total cholesterol in blood (APO B100) (BAD)
- High-density lipoproteins (HDL) are used to transport excess cholesterol to the liver for elimination (GOOD)
Types of lipoproteins:
Sources of Cholesterol:
Ingestion
- Fatty foods with or without cholesterol
- Saturated fats (products from breaking saturated fats used by hepatocytes to make cholesterol)
→Synthesis in hepatocytes
Lipid Metabolism
- The term lipogenesis means fat synthesis, while lipolysis refers to the oxidation (catabolism) of lipids to yield glucose (which then yields ATP)
- If the body has no immediate needs, lipids are stored in adipose tissue
Lipid Metabolism - Lipogenesis
- Glucose and AAs used be liver and adipose cells to perform lipogenesis
- If ATP needs are met, lipogenesis occurs
- Lipogenesis stimulated by insulin
- Excess carbohydrates, proteins, fats converted into triglycerides
Lipid Metabolism - Lipolysis
begins with separating the glycerol backbone of triglycerides from the 3 fatty acids
If ATP supply is LOW in cells…
If ATP supply is high in cells, Glyceraldehyde 3-P converted to glucose (gluconeogenesis)
Beta oxidation
- is the process of cleaving off 2-carbon fragments from long fatty acid chains
- The 2-carbon acetyl groups are joined to coenzyme A to form acetyl CoA for insertion into Krebs cycle
Lipid Metabolism
The oxidation of triglycerides (specifically, the 3 carbon glycerol backbone), results in the formation of ketoacids, (ketone bodies) which must be eliminated by the kidneys in order to maintain homeostasis
Ketogenesis
- is a normal part of fat breakdown, but an excess will cause a metabolic acidosis
- A mild ketoacidosis can occur even with a short 24 hour fast, and is responsible for the headaches and some of the other symptoms that are part of fasting
Protein Metabolism
- Proteins are not a primary source of energy; and unlike lipids and sugars, proteins are not stored
- Yet a certain amount of protein catabolism occurs in the body each day as proteins from worn-out cells are broken down into amino acids
- Some amino acids are converted into other amino acids, peptide bonds are re-formed, and new proteins are synthesized as part of the recycling process
- Yet a certain amount of protein catabolism occurs in the body each day as proteins from worn-out cells are broken down into amino acids
Protein Metabolism
- In protein synthesis, transamination refers to the transfer of an amino group (NH2) to pyruvic acid or another acid in the Krebs cycle to form an amino acid
- In protein catabolism, deamination refers to the removal of an amino group leaving the carbons of a carboxylic acid to be used to make ATP
- Essential amino acids are the 10 amino acids that can’t be synthesized by the body
- Non-essential amino acids are the others that can be synthesized by the body
Metabolic Crossroads
Three pivotal molecules stand at the crossroads of many of the chemical reactions in carbohydrate, lipid, and protein metabolism: acetyl-CoA, glucose-6-phosphate, and pyruvic acid occupy these key entry points into, and out of the Krebs cycle
Metabolic Adaptation:
During the Absorptive State
ingested nutrients enter the blood stream and glucose is readily available
Metabolic Adaptation:
During the Postabsorptive state
- absorption of nutrients from GI tract is complete and energy needs must be met by fuels in the body
- Maintaining a steady blood glucose is critical because the nervous system and red blood cells depend solely on glucose as an energy source
- The effects of insulin dominate
- Maintaining a steady blood glucose is critical because the nervous system and red blood cells depend solely on glucose as an energy source
The Absorptive State
- Soon after a meal glucose, amino acids, and lipid nutrients enter the blood. Triglycerides enter the blood carried in large lipoproteins called chylomicrons. There are 2 metabolic hallmarks of this state:
- Glucose is oxidized to produce ATP in all body cells
- Any excess fuel molecules are stored in hepatocytes, adipocytes, and skeletal muscle cells
- Pancreatic beta cells begin to release insulin to promote entry of glucose and amino acids into cells
The Absorptive State
During the absorptive state, most body cells are concerned with producing ATP by oxidizing glucose
The Postabsorptive State
- About 4 hours after the last meal absorption in the small intestine is nearly complete and blood glucose levels start to fall. The main metabolic challenge at this point is to maintain normal blood glucose levels
- As blood glucose levels decline, insulin secretion falls and glucagon secretion increases
- Blood glucose levels are sustained by the breakdown of liver glycogen, lipolysis, and gluconeogenesis using lactic acid and/or amino acids
- As blood glucose levels decline, insulin secretion falls and glucagon secretion increases
The Postabsorptive State
The process is supported by sympathetic nerve endings that release norepinephrine, and by the adrenal medulla that releases epinephrine and norepinephrine directly into the blood
Basal Metabolic Rate
- The metabolic rate is the overall rate at which metabolic reactions use energy. Basal metabolic rate (BMR) is measured with the body in a quiet, fasting condition
- Whatever the metabolic rate (other than death!), heat is a constant by-product of metabolic reactions, and can be expressed in calories
- The BMR is 1200–1800 Cal/day in adults, or about 24 Cal/kg of body mass in adult males and 22 Cal/kg in adult females
Body Temperature
- Despite wide fluctuations in environmental temperatures, homeostatic mechanisms maintain a normal range for internal (core) body temperature at 37°C (98.6°F)
- Peripheral tissues can be much cooler (“shell temperature 1-6°C lower)
- Body temperature is maintained by hormonal regulation of the BMR, exercise, and sympathetic nervous system stimulation
- Peripheral tissues can be much cooler (“shell temperature 1-6°C lower)
Heat and Energy Balance
- Heat loss occurs through:
- Conduction to solid materials in contact with the body, e.g. walking barefoot on the floor
- Convection is the transfer of heat when a gas or liquid flows over an object, e.g. using a fan on a hot day
- Thermal radiation is the transfer of heat in the form of electromagnetic energy (infrared, and encompassing visible light) between two bodies not in contact
- Evaporation occurs when converting a liquid to a gas
The Hypothalamic Thermostat
- The control center that functions as the body’s thermostat is a group of neurons in the anterior part (preoptic area) of the hypothalamus that receives impulses from thermoreceptors scattered throughout the body
- Neurons of the preoptic area generate nerve impulses at a higher frequency when blood temperature increases, and at a lower frequency when blood temperature decreases
Thermoregulation
- If the core temperature declines, skin blood vessels constrict and thyroid hormones and catecholamines (epinephrine and norepinephrine) are released. Cellular metabolism increases and shivering my ensue
- If core body temperature rises, blood vessels of the skin dilate, sweat glands are stimulated, and the metabolic rate is lowered
Nutrition
- Nutrients are chemical substances in food that body cells use for growth, maintenance, and repair
- There are 6 main types of nutrients
- water , which is needed in the largest amount
- carbohydrates
- lipids
- proteins
- minerals
- vitamins
- There are 6 main types of nutrients
Nutrition
- Guidelines for nutritious eating are not known with certainty. Different populations around the world eat radically different amounts and types of carbohydrates, fats and protein in their diets. Basic guidelines include:
- Eat a variety of foods
- Maintain a healthy weight
- Choose foods low in fat, saturated fat and cholesterol
- Eat plenty of vegetables, fruits and grain products
- Use sugars in moderation only
Nutrition:
**Essential minerals **
- Essential minerals are those inorganic elements that occur naturally in the earth’s crust and are needed to maintain life. The major role of minerals is to help regulate enzymatic reactions and build bone
- Recommendations are to eat foods that contain enough calcium, phosphorus, iron and iodine
- Excess amounts of most minerals are excreted in urine and feces
- Recommendations are to eat foods that contain enough calcium, phosphorus, iron and iodine
Nutrition:
Vitamins
- Vitamins are organic nutrients required in small amounts to maintain growth and normal metabolism - they do not provide energy or serve as the body’s building materials
- Most cannot be synthesized by us, and no single food contains all the required vitamins
- They are divided into those that are water soluble (several B vitamins and vitamin C), and those that are fat soluble (A, D, E, K)
- Most vitamins serve as coenzymes
Vitamin Deficiencies
- Vitamin A is needed to make the visual pigment retinal
- Deficiency leads to night blindness and a weakened immune system
- Vitamin D is needed for calcium absorption
- Deficiency results in impaired bone mineralization, and leads to bone softening diseasess such as rickets in children and osteomalacia in adults
- Vitamin K is needed to make clotting factors II, VII, and IX, X
- A deficiency such as due to long-term antibiotic therapy or taking anticoagulant medications leads to delayed clotting times
- Vitamin C is necessary for proper growth of connective tissues like collagen
- Deficiency manifests as a disease called Scurvy
- Niacin (B3) is a precursor to NAD (NADH), which plays essential metabolic roles in living cells
- A deficiency (which is called Pellagra) results from an all corn diet, and manifests as dermatitis, diarrhea, and dementia
- Thiamine (B1) is essential for neural function and carbohydrate metabolism
- A deficiency (called Beriberi) results from a polished rice diet, and manifests with muscle wasting, and impaired reflexes
- Folic Acid (vitamin B9) is needed to synthesize the bases used to replicate DNA
- A deficiency manifests as a macrocytic anemia without nerve involvement
- Cyanocobalamin (B12 ) is important for normal nerve function and for the formation of blood
- A deficiency manifests as pernicious anemia, ataxia, memory loss, weakness, personality and mood changes
Obesity
- Obesity is defined as a body weight 10-20% (or more) above the desirable level because of excess fat
- An explanation for the prevalence of obesity in our society is not universally agreed upon. In a complex interplay, many psychosocial and physiological issues appear to contribute
- Obesity puts an individual at risk for a large number of diseases and conditions – cardiovascular disease predominant
Factors of Obesity
- Factors that are especially prevalent in western society include:
- An abundance of good-tasting food
- Working longer hours (less time preparing good food)
- Fast-foods
- Super-size portions
- Sedentary jobs
- Lack of Exercise
The thermostat and food intake regulating center of the body is in the ________ of the brain.
Hypothalamus
The three key molecules of metabolism are ________, ________, and ________
- glucose
- Pyruvic Acid
- Acetyl CoA
**T or F: **Vitamins A, B, D, and K are fat‐soluble vitamins.
False
T or F: Foods that we eat are used to supply energy for life processes, serve as building blocks for synthesis reactions, or are stored for future use.
True
NAD+ and FAD (1) are both derivatives of B vitamins, (2) are used to carry hydrogen atoms released during oxidation reactions, (3) become NADH and FADH2 in their reduced forms, (4) act as coenzymes in the Krebs cycle, (5) are the final electron acceptors in the electron transport chain.
a. 1, 2, 3, 4, and 5 b. 2, 3, and 4 c. 2 and 4 d. 1, 2, and 3 e. 1, 2, 3, and 4
e. 1, 2, 3, and 4
During glycolysis, (1) a 6‐carbon glucose is split into two 3‐carbon pyruvic acids, (2) there is a net gain of two ATP molecules, (3) two NADH molecules are oxidized, (4) moderately high levels of oxygen are needed, (5) the activity of phosphofructokinase determines the rate of the chemical reactions.
a. 1, 2, and 3 b. 1 and 2 c. 1, 2, and 5 d. 2, 3, 4, and 5 e. 1, 2, 3, 4, and 5
c. 1, 2, and 5
If glucose is not needed for immediate ATP production, it can be used for (1) vitamin synthesis, (2) amino acid synthesis, (3) gluconeogenesis, (4) glycogenesis, (5) lipogenesis.
a. 1, 3, and 5 b. 2, 4, and 5 c. 2, 3, 4, and 5 d. 1, 2, and 3 e. 2 and 5
b. 2, 4, and 5
Which of the following is the correct sequence for the oxidation of glucose to produce ATP?
a. electron transport chain, Krebs cycle, glycolysis, formation of acetyl CoA b. Krebs cycle, formation of acetyl CoA, electron transport chain, glycolysis c. glycolysis, electron transport chain, Krebs cycle, formation of acetyl CoA d. glycolysis, formation of acetyl CoA, Krebs cycle, electron transport chain e. formation of acetyl CoA, Krebs cycle, glycolysis, electron transport chain.
d. glycolysis, formation of acetyl CoA, Krebs cycle, electron transport chain
Which of the following would you not expect to experience during fasting or starvation?
a. decrease in plasma fatty acid levels b. increase in ketone body formation c. lipolysis d. increased use of ketones for ATP production in the brain e. depletion of glycogen
a. decrease in plasma fatty acid levels
If core body temperature rises above normal, which of the follow‐ing would occur to cool the body? (1) dilation of vessels in the skin, (2) increased radiation and conduction of heat to the environment, (3) increased metabolic rate, (4) evaporation of perspiration, (5) increased secretion of thyroid hormones.
a. 3, 4, and 5 b. 1, 2, and 4 c. 1, 2, and 5 d. 1, 2, 3, 4 and 5 e. 1, 2, 4, and 5
b. 1, 2, and 4
In which of the following situations would the metabolic rate increase? (1) sleep, (2) after ingesting food, (3) increased secretion of thyroid hormones, (4) parasympathetic nervous system stimulation, (5) fever.
a. 3 and 4 b. 1, 3, and 5 c. 2 and 3 d. 2, 3, and 4 e. 2, 3, and 5
e. 2, 3, and 5
Which of the following are absorptive state reactions? (1) aerobic cellular respiration, (2) glycogenesis, (3) glycogenolysis, (4) gluconeogenesis using lactic acid, (5) lipolysis.
a. 1 and 2
b. 2 and 3
c. 3 and 4
d. 4 and 5
e. 1 and 5
b. 2 and 3
Match the hormones with the reactions they regulate (answers may be used more than once; some reactions have more than one answer):
___ a.____gluconeogenesis
___ b.____glycogenesis
___ c.____glycogenolysis
___ d.____lipolysis
___ e.____lipogenesis
___ f.____protein catabolism
___ g.____protein anabolism
- insulin
- cortisol
- glucagon
- thyroid hormones
- epinephrine
- insulinlike growth factors
2,3 a.____gluconeogenesis
1 b.____glycogenesis
3,5 c.____glycogenolysis
2,4,5,6 d.____lipolysis
1 e.____lipogenesis
2 f.____protein catabolism
1,2,4,6 g.____protein anabolism
Match the following:
___ a. ____deliver cholesterol to body cells for use in repair of membranes and synthesis of steroid hormones and bile salts
___ b. ____remove excess cholesterol from body cells and transport it to the liver for elimination
___ c. ____organic nutrients required in small amounts for growth and normal metabolism
___ d. ____the energy‐transferring molecule of the body
___ e. ____nutrient molecules that can be oxidized to produce ATP or stored in adipose tissue
___ f. ____transport endogenous lipids to adipocytes for storage
___ g.____the body’s preferred source for synthesizing ATP
___ h.____composed of amino acids and are the primary regulatory molecules in the body
___ i.____acetoacetic acid, beta‐hydroxybutyric acid, and acetone
___ j.____hormone secreted by adipocytes that acts to decrease total body‐fat mass
___ k.____neurotransmitter that stimulates food intake
___ l.____inorganic substances that perform many vital functions in the body
___ m.____carriers of electrons in the electron transport chain
- leptin
- minerals
- glucose
- lipids
- proteins
- neuropeptide Y
- cytochromes
- ketone bodies
- low‐density lipoproteins
- ATP
- vitamins
- high‐density lipoproteins
- very‐low‐density lipoproteins
Match the following:
9 a. ____deliver cholesterol to body cells for use in repair of membranes and synthesis of steroid hormones and bile salts
12 b. ____remove excess cholesterol from body cells and transport it to the liver for elimination
11 c. ____organic nutrients required in small amounts for growth and normal metabolism
10 d. ____the energy‐transferring molecule of the body
4 e. ____nutrient molecules that can be oxidized to produce ATP or stored in adipose tissue
13 f. ____transport endogenous lipids to adipocytes for storage
3 g.____the body’s preferred source for synthesizing ATP
5 h.____composed of amino acids and are the primary regulatory molecules in the body
8 i.____acetoacetic acid, beta‐hydroxybutyric acid, and acetone
1 j.____hormone secreted by adipocytes that acts to decrease total body‐fat mass
6 k.____neurotransmitter that stimulates food intake
2 l.____inorganic substances that perform many vital functions in the body
7 m.____carriers of electrons in the electron transport chain
Match the following:
___ a.____the mechanism of ATP generation that links chemical reactions with pumping of hydrogen ions
___ b.____the removal of electrons from an atom or molecule resulting in a decrease in potential energy
___ c.____the transfer of an amino group from an amino acid to a substance such as pyruvic acid
___ d.____the formation of glucose from noncarbohydrate sources
___ e.____refers to all the chemical reactions in the body
___ f.____the oxidation of glucose to produce ATP
___ g.____the splitting of a triglyceride into glycerol and fatty acids
___ h.____the synthesis of lipids
___ i.____the addition of electrons to a molecule resulting in an increase in potential energy content of the molecule
___ j.____the formation of ketone bodies
___ k.____the breakdown of glycogen back to glucose
___ l.____exergonic chemical reactions that break down complex organic molecules into simpler ones
___ m.____overall rate at which metabolic reactions use energy
___ n.____the breakdown of glucose into two molecules of pyruvic acid
___ o.____removal of CO2 from a molecule
___ p.____endergonic chemical reactions that combine simple molecules and monomers to make more complex ones
___ q.____the addition of a phosphate group to a molecule
___ r.____the removal of the amino group from an amino acid
___ s.____the cleavage of one pair of carbon atoms at a time from a fatty acid
___ t.____the conversion of glucose into glycogen
- metabolism
- catabolism
- beta oxidation
- lipolysis
- phosphorylation
- glycolysis
- cellular respiration
- transamination
- anabolism
- lipogenesis
- glycogenolysis
- glycogenesis
- metabolic rate
- ketogenesis
- oxidation
- reduction
- chemiosmosis
- deamination
- gluconeogenesis
- decarboxylation
17 a.____the mechanism of ATP generation that links chemical reactions with pumping of hydrogen ions
15 b.____the removal of electrons from an atom or molecule resulting in a decrease in potential energy
8 c.____the transfer of an amino group from an amino acid to a substance such as pyruvic acid
19 d.____the formation of glucose from noncarbohydrate sources
1 e.____refers to all the chemical reactions in the body
7 f.____the oxidation of glucose to produce ATP
4 g.____the splitting of a triglyceride into glycerol and fatty acids
10 h.____the synthesis of lipids
16 i.____the addition of electrons to a molecule resulting in an increase in potential energy content of the molecule
14 j.____the formation of ketone bodies
11 k.____the breakdown of glycogen back to glucose
2 l.____exergonic chemical reactions that break down complex organic molecules into simpler ones
13 m.____overall rate at which metabolic reactions use energy
6 n.____the breakdown of glucose into two molecules of pyruvic acid
20 o.____removal of CO2 from a molecule
9 p.____endergonic chemical reactions that combine simple molecules and monomers to make more complex ones
5 q.____the addition of a phosphate group to a molecule
18 r.____the removal of the amino group from an amino acid
3 s.____the cleavage of one pair of carbon atoms at a time from a fatty acid
12 t.____the conversion of glucose into glycogen
Before the nutrients in a cheeseburger can be absorbed in the small intestine, the complex carbohydrates, fats, and proteins contained in it must undergo
a. exergonic catabolic reactions
b. endergonic catabolic reactions
c. exergonic anabolic reactions
d. endergonic anabolic reactions
e. endergonic reactions which are both catabolic and anabolic.
a. exergonic catabolic reactions
Glucose is stored in the liver and muscle in the form of
a. starch.
b. cellulose
c. triglycerides.
d. glycogen
e. glucagon
a. starch
Which of the following places the events of glucose catabolism in the correct order?
a. glycolysis, formation of acetyl coA, Krebs cycle, electron transport chain reactions
b. glycolysis, Krebs cycle, formation of acetyl coA, electron transport chain reactions
c. glycolysis, anaerobic respiration, Krebs cycle, electron transport chain reactions
d. glycolysis, Krebs cycle, anaerobic respiration, electron transport chain reactions
e. formation of acetyl coA, glycolysis, electron transport chain reactions.
a. glycolysis, formation of acetyl coA, Krebs cycle, electron transport chain reactions
High-density lipoproteins
a. remove excess cholesterol from the blood.
b. transport dietary lipids to adipose tissue for storage.
c. transport triglycerides to adipose tissue for storage.
d. remove fatty acids from chylomicron triglycerides.
e. deposit cholesterol in and around arteries.
a. remove excess cholesterol from the blood.
Fatty acids may be converted to acetyl CoA through a process called ________.
a. dehydrogenation
b. gluconeogenesis
c. beta oxidation
d. ketogenesis
e. transamination
c. beta oxidation
Essential amino acids
- are found in complete proteins.
- include phenylalanine and tryptophan.
- are found only in animal protein sources.
a. 1 only
b. 2 only
c. 3 only
d. 1 and 2 are correct.
1, 2, and 3 are correct.
d. 1 and 2 are correct.
Which of the following may be used to produce ATP without utilizing glucose?
a. oxidation of fatty acids
b. oxidation of lactic acid
c. oxidation of amino acids
d. oxidation of ketone bodies
e. all of these choices
e. all of these choices
The bulk of your total energy expenditure is due to your
a. voluntary exercise.
b. nonexercise activity thermogenesis.
c. basal metabolic rate.
d. food-induce thermogenesis.
e. energy homeostasis.
c. basal metabolic rate.
Vitamins
a. serve as coenzymes
b. provide energy
c. serve as building materials within the body
d. serve as coenzymes and provide energy are correct
e. serve as coenzymes, provide energy, and serve as building materials within the body are correct
a. serve as coenzymes
What is the role of oxygen in metabolism?
a. it provides energy to cells
b. it is needed in all oxidation reactions
c. it is a catalyst in the Krebs cycle
d. it is needed to produce ATP
e. it is the final electron acceptor in the electron transport system
e. it is the final electron acceptor in the electron transport system
