digestion and metabolism Flashcards
LEARNING OBJECTIVES 1. List and describe the major processes occurring during digestive system activity. 2. Describe the tissue composition and the general function of each of the four layers of the alimentary canal. 3. Describe the basic functions of the mouth, pharynx and oesophagus. Include a brief description of the functions of saliva. 4. Outline the basic anatomy of the stomach, small intestine and large intestine and the digestive processes that occur in these locations. 5.
1
Q
In order what are the six major processes involved in digestion?
A
- Ingestion
- Propulsion
- Mechanical breakdown
- Chemical digestion
- Absorption
- Defaecation
2
Q
what areas of the body involve mechanical breakdown?
A
mouth: chewing and mixing food with saliva
stomach: churning and mixing with gastric juice
small intestine: segmentation = mixes food with digestive juices and aids in nutrient absorption
3
Q
What are the names of the 4 basic layers of the alimentary canal and what are they made of?
A
Serosa- epithelium and connective tissue
Muscularis externa- longatudinal muscle and circular muscle
Submusosa - loose connective tissue with elastic
Mucosa- Epithelium, lamina propia and muscularis mucisae
4
Q
What is the function of the Mucosa layer of the alimentary canal?
A
_Mucosa - The most inner laye which is made up of three subay _
- Epithelium: secretes mucus protects the mucosa, helps move food along secretes digestive enzymes chemical digestion secretes hormones control motility and secretion of digestive juices absorbs nutrients.
- Lamina propria: contains capillaries absorption of the end products of digestion, nourishes epithelium lymphoid tissue protection against bacteria and pathogens.
- Muscularis mucosa: produces folds in the mucosa of the small intestine to increase the surface area for absorption
5
Q
What is the structure and function of the Submucosa layer of the alimentary canal?
A
Loose connective tissue with elastic tissue allows stretch and recoil
Rich supply of:
blood vessels: for nutrient absorption
lymphatic vessels: for transports lipids
lymphoid tissue: for immune function
nerves: parasympathetic –> motility and secretion
sympathetic --\> motility and secretion
6
Q
What is the function of the Mucularis externa layer of the alimentary canal?
A
Responsible for peristalsis (propulsion) and segmentation (mechanical breakdown).
Two smooth muscle layers:
- inner circular - form sphincters act as valves to control the passage of food
- outer longitudinal
7
Q
What is the function of the Serosa layer of the alimentary canal?
A
Connective tissue covered with a thin layer of squamous epithelium.
Functions: protection of the alimentary canal anchors the alimentary tissues within the peritoneal cavity
8
Q
What are the functions of the mouth?
A
Digestive functions of the oral cavity (mouth):
- Ingestion
- Mastication (chewing) - mechanical breakdown
- Mixing food with saliva
- Taste sensation
- Initiating chemical digestion - amylase begins chemical digestionoof charbohydrates only
- Propulsion - swallowing food (deglutition)
9
Q
Chemical digestion is initiated in the mouth. What enzymes are secereted in the mouth and what do they break down?
A
Amylase begins chemical digestion of charbohydrates only.
Lingual lipase- begins break down of small chain fats
10
Q
Describe what happends in box A.
A
Glycolysis- Glucose is turned into Pyruvic Acid
11
Q
What do the purple arrows signify?
A
Anabolic reactions
12
Q
What do the blue arrows signify?
A
Catabolic reactions
13
Q
Where abouts in the cell does stage 2 occur in the cell?
A
cytoplasm
14
Q
Where abouts in a cell does stage 3 occur?
A
mitocondria
15
Q
what is the name of the intermediate molecule that each of the nutrients are eventualy converted to?
A
They are all broken down into Acytyl Co enzyme A
16
Q
What is the name of the series of reactions that occur in the green box?
A
The Krebs Cycle
17
Q
What are the three things made by the Krebs Cycle?
A
Carbon dioxide
Hydrogen Ions
ATP
18
Q
what happens to excess glucose in the body?
A
It is turned into Glycogen through the process called glycogenisis and stored as fat.
19
Q
What is the process labels A?
A
Electron transport chain
20
Q
What molecule must be removed from amino acids beofre they can be used in this series of reactions?
A
Ammonia
21
Q
What molecules are used in energy production in most tissues excluding nervous tissue?
A
fatty acids
keytones
glycerol
22
Q
What is the hormone that donminate stage three?
A
Insulin
23
Q
Why does the liver have a dual blood supply?
A
To supply it with blooth oxygen rich blood and nutrient rich blood.
The hepatic artery supplies the liver with oxygenated blood from the lungs, and the portal vein supplies it with nutrient-rich blood from the intestines.
24
Q
The liver has two routes of blood supply. Which vessel supplirs blood from the small intestine and which supplies blood from the systemic circulation? And which percentage comes from each vessel?
A
Systemic circulation- Hepatic artery
Small intestine- Hepatic portal vein
25
The liver plays a vital role in stabilising blood glucose leves around 5mmol/L. What three processes occur in the liver to maintain glucose homeostasis and when so these precesses take place (eg glucose too high or too low).
1. Glycogenisis - too much glucose in blood steam
2. Glycogenalysis - not enough glucose in blood stream
3. Gluconeogenisis - not enough glucose in blood steam = make glucose from non-glucose stores
26
What are the names of the three glands the mouth?
27
What are the functions of the stomach?
1. Mechanical breakdown – mixing food with gastric juice (i.e. liquefaction of food chyme)
2. Chemical digestion (proteins)
3. Absorption (fat-soluble substances ONLY, e.g. alcohol)
4. Storage of food
5. Propulsion – to the small intestine
6. Secretion of Intrinsic factor \<--- only essential function of the stomach
28
What is the empty and full volume of the stomach?
50ml empty
4L when full
29
what are the internal folds of the stomach lining called?
Rugae
30
Describe the structure and function of the muscularis externa (modified) of the stomach.
Structure- circular & longitudinal Function- mix, churn and propel food and the oblique muscle pummels the food and rams it into the small intestine
31
What is the structure and finction of the stomach muscosa.
This includes the types of cells and what they produce
Structurte of mucosa- lining of simple columnar epithelium that produces an alkaline mucous, dotted with: _gastric pits_ that contain mucous cells
These gastric glands produce 3L of
gastric juice per day,
These glands include:
_chief cells_ – secrete pepsinogen
_parietal cells_ – secrete HCl
_enteroendocrine cells_ – secrete hormones that control gut motility and secretion
32
Which cells produce pepsinogen and which cells produce HCl? Where are these cells found?
chief cells – secrete pepsinogen
parietal cells – secrete HCl
Found in the stomach
33
Gastric juice creates a harsh environment HCl is corrosive. Protein digesting enzymes (proteases) can digest the stomach wall. For this reason the body has a three layered mucosal barrier. What are the three layers?
1. _bicarbonate-rich fluid under an insoluble mucus_ on the stomach wall. Bicarbonate-ion rich musus nutralises acid that might get through the insoluble alkaline mucus.
2. mucosal epithelial cells joined by _tight junctions_
3. damaged mucosal epithelial cells shed and _quickly replaced_
34
What happeneds then the mucosal layer of the stomach is broken?
Leads to gastritis. Persistant damage leads to a gastic ulcer.
35
what is the basic structure and function of the small intestines?
To absorb as much nutrience as possible we want to have as much sueface area as possible.
36
what are the tree sections of the small intestine?
Duodenum
Jejunum
Ilium
37
Which section of the small intestine recieves bile and pancreatic juices?
Duodenum
38
Which section of the small intestine is the major site of chemical and mechanical degestion as well as absorption?
Jejunum
39
How is the small intestine adapted for nutrient absorption?
- length
- mucosa/submucosa
- circular folds
- villi
- microvilli
40
What is the function of the circular folds in the sall intestine?
To slow the movement of chyme and thus increasing the time for nutirent absoption
41
What do the micovilli of the small intestines do?
Very small, densely packed villi on the surface of
individual absorptive epithelial cells form the “brush
border”
Plasma membrane bears enzymes that _complete
carbohydrate, protein and nucleic acid digestion_(brush
border enzymes)
42
What is the function of the villi in the small intestines?
nutrient and electrolyte absorption - epithelial columnar cells, core contains a capillary bed a
produce mucous - goblet cells
43
What are intestinal crypts?
Intestinal crypts are are tubular glands locared in pits between villi. They secrete slightly alkaline intestinal juice that facilitates nutrient absorption.
Enteroendocrine cells produce hormones that simulate the secretion of bile and pancreatic juice.
44
what percentage of nutrienet absorption occurs in the small intestine?
90%
45
as chyme is passed from the stomach into the small intestine what stops the stomach acids from eating away at the walls of the intestines?
alkline intestinal mucus ans pancreatic juices help nutralise acidic chyme
46
which enzyme completes the digestion of carbohydrates, protien, and nuckeic acids?
Brush border enzymes
47
once the nutrience in absorbed in the small intestines where does it go? (water soluble and lipid solulbe go different places)
- nutrients (water soluble) absorbed into blood travel in the hepatic portal vein to the liver
- nutrients (lipid soluble) absorbed into the lymphatic circulation enter the blood at the thoracic duct
48
why are there circular folds in the small intestine?
to slow the movement of chyme and thus increasing the time fofr nutriene to be absorbed. (1cm tall)
49
The function of the hepatic portal circulation is to:
a. carry toxins to the venous system for disposal through the urinary tract.
b. collect absorbed nutrients for metabolic processing or storage before releasing them to the circulation for cellular use.
c. distribute hormones
d. return glucose to the general circulation when blood sugar is lowThe function of the hepatic portal circulation is to:
a. carry toxins to the venous system for disposal through the urinary tract.
b. collect absorbed nutrients for metabolic processing or storage before releasing them to the circulation for cellular use.
c. distribute hormones
d. return glucose to the general circulation when blood sugar is low vThe function of the hepatic portal circulation is to:
a. carry toxins to the venous system for disposal through the urinary tract.
b. collect absorbed nutrients for metabolic processing or storage before releasing them to the circulation for cellular use.
c. distribute hormones
d. return glucose to the general circulation when blood sugar is lowThe function of the hepatic portal circulation is to:
a. carry toxins to the venous system for disposal through the urinary tract.
b. collect absorbed nutrients for metabolic processing or storage before releasing them to the circulation for cellular use.
c. distribute hormones
d. return glucose to the general circulation when blood sugar is lowThe function of the hepatic portal circulation is to:
a. carry toxins to the venous system for disposal through the urinary tract.
b. collect absorbed nutrients for metabolic processing or storage before releasing them to the circulation for cellular use.
c. distribute hormones
d. return glucose to the general circulation when blood sugar is lowThe function of the hepatic portal circulation is to:
a. carry toxins to the venous system for disposal through the urinary tract.
b. collect absorbed nutrients for metabolic processing or storage before releasing them to the circulation for cellular use.
c. distribute hormones
d. return glucose to the general circulation when blood sugar is lowThe function of the hepatic portal circulation is to:
a. carry toxins to the venous system for disposal through the urinary tract.
b. collect absorbed nutrients for metabolic processing or storage before releasing them to the circulation for cellular use.
c. distribute hormones
d. return glucose to the general circulation when blood sugar is lowThe function of the hepatic portal circulation is to:
a. carry toxins to the venous system for disposal through the urinary tract.
b. collect absorbed nutrients for metabolic processing or storage before releasing them to the circulation for cellular use.
c. distribute hormones
d. return glucose to the general circulation when blood sugar is lowThe function of the hepatic portal circulation is to:
a. carry toxins to the venous system for disposal through the urinary tract.
b. collect absorbed nutrients for metabolic processing or storage before releasing them to the circulation for cellular use.
c. distribute hormones
d. return glucose to the general circulation when blood sugar is low
b. collect absorbed nutrients for metabolic processing or storage before releasing them to the circulation for cellular use.
50
The chemical and mechanical process of food breakdown are called:
a. digestion
b. absorption
c. ingestion
d. secretion
a. digestion
51
When we ingest large molecules such as lipids, carbohydrates, and proteins, they must undergo catabolic reactions whereby enzymes split these molecules. This series of reactions is called:
a. absorption
b. secretion
c. chemical digestion
d. mechanical digestion
c. chemical digestion
52
The sheets of peritoneal membrane that hold the digestive tract in place are called:
a. mesenteries
b. lamina propria
c. serosal lining
d. mucosal liningThe sheets of peritoneal membrane that hold the digestive tract in place are called:
a. mesenteries
b. lamina propria
c. serosal lining
d. mucosal liningThe sheets of peritoneal membrane that hold the digestive tract in place are called:
a. mesenteries
b. lamina propria
c. serosal lining
d. mucosal liningThe sheets of peritoneal membrane that hold the digestive tract in place are called:
a. mesenteries
b. lamina propria
c. serosal lining
d. mucosal liningThe sheets of peritoneal membrane that hold the digestive tract in place are called:
a. mesenteries
b. lamina propria
c. serosal lining
d. mucosal liningThe sheets of peritoneal membrane that hold the digestive tract in place are called:
a. mesenteries
b. lamina propria
c. serosal lining
d. mucosal liningThe sheets of peritoneal membrane that hold the digestive tract in place are called:
a. mesenteries
b. lamina propria
c. serosal lining
d. mucosal liningThe sheets of peritoneal membrane that hold the digestive tract in place are called:
a. mesenteries
b. lamina propria
c. serosal lining
d. mucosal lining
a. mesenteries
53
From the esophagus to the anal canal, the walls of every organ of the alimentary canal are made up of the same four basic layers. Arrange them in order from lumen.
a. muscularis externa, serosa, mucosa, and submucosa
b. serosa, mucosa, submucosa, and muscularis externa
c. submucosa, serosa, muscularis externa, and mucosa
d. mucosa, submucosa, muscularis externa, and serosa
d. mucosa, submucosa, muscularis externa, and serosa
54
Chyme is created in the
a. mouth
b. stomach
c. esophagus
d. small intestine
b. stomach
55
Hydrochloric acid is secreted by which of the secretory cells of the stomach?
a. chief cells
b. parietal cells
c. serous cells
d. mucous neck cells
b. parietal cells
56
Gastrin, histamine, endorphins, serotonin, cholecystokinin, and somatostatin are hormones that are released directly into the lamina propria. Which of the following cell types synthesize and secrete these products?
a. enteroendocrine cells
b. parietal cells
c. zymogenic cells
d. mucous neck cells
a. enteroendocrine cells
57
There are three phases of the gastric secretion. The cephalic phase occurs:
a. Before food enters the stomach and is triggered by aroma, sight, or thought.
b. Immediately after food enters the stomach, preparing the small intestine for the influx of a variety of nutrients.
c. At the end of a large meal, and the juices secreted are powerful and remain in the GI tract for a long period of time.
d. When the meal is excessively high in acids and neutralization is required.
a. Before food enters the stomach and is triggered by aroma, sight, or thought.
58
Peristaltic waves are:
a. segmental regions of the gastrointestinal tract
b. churning movements of the gastrointestinal tract
c. pendular movements of the gastrointestinal tract
d. waves of muscular contractions that propel contents from one point to another
d. waves of muscular contractions that propel contents from one point to another
59
Gastrin is a digestive hormone that is responsible for the stimulation of acid secretions in the stomach. These secretions are stimulated by the presence of:
a. starches and complex carbohydrates
b. protein and peptide fragments
c. simple carbohydrates and alcohols
d. fatty acids
b. protein and peptide fragments
60
You have just eaten a meal high in complex carbohydrates. Which of the following enzymes will help to digest the meal?
a. gastrin
b. amylase
c. cholecystokinin
d. trypsin
b. amylase
61
The ducts that deliver bile and pancreatic juice from the liver and pancreas, respectively, unite to form the:
a. portal vein
b. pancreatic acini
c. bile canaliculus
d. hepatopancreatic ampulla
d. hepatopancreatic ampulla
62
The enzymatic breakdown of any type of food molecule is called
a. diffusion
b. active transport
c. hydrolysis
d. denatured
c. hydrolysis
63
Secretin is an enzyme that is liberated by the small intestinal mucosa in response to:
a. acidic chyme entering the small intestine
b. irritation in the lining of the stomach
c. distention of the stomach
d. the enterogastric reflex
a. acidic chyme entering the small intestine
64
Short-chain triglycerides found in foods such as butterfat molecules in milk are split by a specific enzyme in preparation for absorption. Which of the following enzymes is responsible?
a. rennin
b. pepsin
c. lipase
d. cholecystokinin
c. lipase
65
Hepatocytes do not:
a. produce digestive enzymes
b. process nutrients
c. store fat-soluble vitamins
d. detoxify
a. produce digestive enzymes
66
Which of the following is not a phase of gastric secretion?
a. cephalic
b. gastric
c. intestinal
d. enterogastric
d. enterogastric
67
Which vitamin requires intrinsic factor in order to be absorbed?
a. B12
b. K
c. A
d. C
a. B12
68
Due to hepatic action, a comparison of blood entering and leaving the liver shows that:
a. blood leaving the liver contains more glucose
b. blood leaving the liver contains more amino acids
c. blood leaving the liver usually has more ingested toxic substances
d. blood leaving the liver via the hepatic vein contains fewer nutrients and waste material than the blood that entered it
d. blood leaving the liver via the hepatic vein contains fewer nutrients and waste material than the blood that entered it
69
Chemical digestion reduces large complex molecules to simpler compounds by the process of:
a. mastication
b. catabolism
c. anabolism
d. fermentation
b. catabolism
70
The solutes contained in saliva include:
a. only salts and minerals
b. only proteases and amylase
c. mucin, lysozyme, electrolytes, salts and minerals
d. electrolytes digestive enzyme, mucin, lysozyme, wastes and IgA
d. electrolytes digestive enzyme, mucin, lysozyme, wastes and IgA
71
The terminal portion of the small intestine is know as the:
a. duodenum
b. ileum
c. jejunum
d. pyloric sphincter
b. ileum
72
Digestion of which of the following would be affected the most if the liver were severely damaged?
a. lipids
b. carbohydrates
c. proteins
d. starches
a. lipids
73
\_\_\_\_\_\_\_\_\_ is locally regulated in the blood by the active form of vitamin D, which acts as a cofactor.
a. Iron
b. Sodium
c. Phosphorus
d. Calcium
d. Calcium
74
As the food in the stomach is repeatedly squeezed and mixed with gastric juice, it is converted into a creamy paste called:
a. a bolus
b. chyme
c. bile
d. feces
b. chyme
75
The function of the goblet cells is to:
a. absorb nutrients from digested food and store them for future use
b. produce mucus that protects parts of the digestive organs from the effects of powerful enzymes needed for food digestion
c. secrete buffers in order to keep the PH of the digestive tract close to neutral
d. provide protection against invading bacteria and other disease-causing organisms
b. produce mucus that protects parts of the digestive organs from the effects of powerful enzymes needed for food digestion
76
c Under normal conditions, the gastric mucosa pours out as much as:
a. 10 liters of gastric juice per hour
b. 1 pint of gastric juice following each meal.
c. 2 to 3 liters of gastric juice per day
d. 6 liters of gastric juice when the meal is usually heavy in fats
c. 2 to 3 liters of gastric juice per day
77
Which of the following enzymes is specific for proteins?
a. dextrinase
b. amylase
c. trypsin
d. lipase
c. trypsin
78
The major function of the large intestine is to:
a. secrete digestive enzymes
b. remove waste materials
c. regulate the release of bile
d. reabsorb 95% of ingested water
b. remove waste materials
79
The site of production of secretin and cholecystokinin is the:
a. stomach
b. pancreas
c. small intestine
d. large intestine
c. small intestine
80
A fluid secreted in the small intestine during digestion that contains cholesterol, emulsification agents, and phospholipids is:
a. bile
b. pancreatic juice
c. intestinal juice
d. gastric juice
a. bile
81
The layer of the digestive tube that contains blood vessels, lymphatic nodes, and a rich supply of elastic fiber is the:
a. mucosa
b. submucosa
c. muscularis externa
d. serosa
b. submucosa
82
Chemical digestion in the small intestine involves:
a. a significant amount of enzyme secretion by the intestinal mucosa
b. cholecystokinin (CCK), an intestinal hormone responsible for gallbladder contraction
c. Secretions from the spleen that contain all enzymes necessary for complete digestion
d. Bile salts that help emulsify carbohydrates so that they can be easily digested by enzymatic action
b. cholecystokinin (CCK), an intestinal hormone responsible for gallbladder contraction
83
Select the correct enzyme/substrate combination:
a. amylase: starches
b. chymotrypsin: neutral fats
c. nucleases: proteins
d. amylase: starches and nucleases: proteins
a. amylase: starches
84
You have just eaten French fries, buttered toast, ice cream and whole milk. Which of the following glands would be active in helping you digest this food?
a. the pancreas
b. the buccal glands
c. the thyroid gland
d. the parotid glands
a. the pancreas
85
The ingestion of a meal high in fat content would cause which of the following to occur?
a. Sever indigestion would occur, caused by the lack of sufficient digestive enzymes.
b. This type of food would cause secretion of gastrin to cease, causing digestive upset.
c. Bile would be released from the gallbladder to emulsify the fat in the duodenum.
d. The acid secretions from the stomach would be sufficient to digest this food.
c. Bile would be released from the gallbladder to emulsify the fat in the duodenum.
86
The absorptive effectiveness of the small intestines is enhanced by increasing the surface area of the mucosal lining. Which of the following accomplish this task?
a. plicae circularis and intestinal wall
b. the vast array of digestive enzymes
c. brunner glands
d. the rugae
a. plicae circularis and intestinal wall
87
Which of the following is not true of saliva?
a. cleanses the mouth
b. contains enzymes that begin the breakdown of proteins
c. moistens food and aids in compacting of the bolus
d. dissolves food chemicals so they can tasted
b. contains enzymes that begin the breakdown of proteins
88
In addition to storage and mechanical breakdown of food the stomach:
a. initiates protein digestion and denatures proteins
b. is the first site where absorption takes place
c. is the only place where fats are completely digested
d. is the first site where chemical digestion of starch takes place
a. initiates protein digestion and denatures proteins
89
The molecule that serves as the major source of readily available body fuel is:
a. fat
b. glucose
c. acetyl CoA
d. cellulose
b. glucose
90
Dietary fats are important because:
a. They keep blood pressure normal.
b. They help the body absorb fat-soluble vitamins.
c. They contribute significantly to the health of the skin.
d. They help prevent the common cold.
b. They help the body absorb fat-soluble vitamins.
91
Which of the following statements best describes "complete protein"?
a. derived from meat and fish only
b. meets all the minimum daily requirements for a sound diet
c. derived from legumes and other plant material
d. must meet all the body's amino acid requirements for maintenance and growth
d. must meet all the body's amino acid requirements for maintenance and growth
92
The term "metabolism" is best defined as:
a. the length of time it takes to digest and absorb fats
b. a measure of carbohydrate utilization
c. the number of calories it takes to keep from shivering on a cold day
d. the sum of energy produced by all the chemical reactions and mechanical work of the body
d. the sum of energy produced by all the chemical reactions and mechanical work of the body
93
The term "energy output" includes:
a. the energy lost as heat
b. the loss of organic molecules in urine
c. the loss or organic molecules in feces
d. the loss of energy to perspiration
a. the energy lost as heat
94
When proteins undergo deamination, a substance found in the urine is:
a. steroids
b. ammonia
c. acetyl CoA
d. ketone bodies
b. ammonia
95
It is important to ensure that your diet is adequately rich in vitamins because:
a. vitamins provide protection against the common cold
b. very few foods contain vitamins
c. most vitamins are coenzymes needed to help the body utilize essential nutrients
d. all vitamins are water-soluble and pass out of the body too quickly to ensure utilization
c. most vitamins are coenzymes needed to help the body utilize essential nutrients
96
Of all of the minerals required by the human body, ___________ and _________ account for three-quarter of the total.
a. zinc, selenium
b. potassium, sodium
c. sulfur, chlorine
d. calcium, phosphorus
d. calcium, phosphorus
97
Anabolism includes reactions in which:
a. carbohydrate utilization increases
b. larger molecules or structures are built from smaller ones
c. structural proteins are used as a potential energy source
d. ketone bodies are formed
b. larger molecules or structures are built from smaller ones
98
Catabolism involves processes that:
a. cause a decline in circulating ketone bodies
b. mobilize fat during the post absorptive state
c. break down complex structures to simpler ones
d. elevate glucagon levels
c. break down complex structures to simpler ones
99
The primary function of cellular respiration is to:
a. determine the amount of heat needed by the human body
b. provide the body with adequate amounts of vitamins and minerals
c. efficiently monitor the energy needs of the body
d. generate ATP, which traps some of the chemical energy of food molecules in its high energy bonds
d. generate ATP, which traps some of the chemical energy of food molecules in its high energy bonds
100
Glycogen is formed in the liver during the:
a. post absorptive state
b. absorptive state
c. starvation period
d. period when the metabolic rate is lowest
b. absorptive state
101
Glycolysis is best defined as the:
a. Conversion of glucose into carbon dioxide and water
b. conversion of glucose into two molecules of pyruvic acid
c. conversion of pyruvic acid into carbon dioxide
d. formation of sugar
b. conversion of glucose into two molecules of pyruvic acid
102
Among the conditions required for measuring the basal metabolic rate is:
a. being in an absorptive state
b. remaining in an upright position
c. keeping the room temperature between 20-25 degrees C
d. sleeping
c. keeping the room temperature between 20-25 degrees C
103
The primary function of carbohydrates is to:
a. contribute to cell structure
b. maintain a large storehouse of glycogen
c. maintain energy production within the cells
d. form functional molecules like hemoglobin and cytochromes
c. maintain energy production within the cells
104
During normal conditions, proteins are essential to the body for all of the following except:
a. production of energy
b. production of some hormones
c. production of enzymes, clotting factors, and antibodies
d. formation of functional molecules like hemoglobin and cytochromes
a. production of energy
105
In carbohydrate metabolism, the carbohydrates:
a. are converted into fat if present in excess
b. such as the monomer galactose are normally used to make ATP
c. are converted into fructose by the liver before they enter into general circulation
d. that are highly refined offer many valuable nutrients in addition to calories
a. are converted into fat if present in excess
106
Minerals are substances that cannot be used for fuel. They:
a. include substance like carbon, hydrogen, and nitrogen
b. are the major electrolytes in the blood
c. help maintain body heat balance
d. help regulate liver by-products
b. are the major electrolytes in the blood
107
As the body progresses from the absorptive to the postabsorptive state, only the ________ continues to burn glucose while every other organ in the body switches to fatty acids
a. liver
b. brain
c. pancreas
d. spleen
b. brain
108
Only the ______ forms urea.
a. kidney
b. pancreas
c. spleen
d. liver
d. liver
109
When ketone bodies are present in the blood and urine in large amounts, it indicates increased metabolism of:
a. amino acids
b. fatty acids
c. glycogen
d. lactic acid
b. fatty acids
110
The pickup molecule for the Krebs cycle is ___________ acid.
a. isocitric
b. fumaric
c. oxaloacetic
d. malic
c. oxaloacetic
111
Gluconeogenesis is the process in which:
a. Glycogen is broken down to release glucose
b. glucose is formed from noncarbohydrate precursors
c. glycogen is formed
d. glucose is converted into carbon dioxide and water
b. glucose is formed from noncarbohydrate precursors
112
elect the correct statement:
a. anabolism is the process of breaking down large substance into smaller ones
b. cellular respiration is a catabolic process
c. during oxidation reactions, substances gain electrons
d. during reduction reactions, substances lose electrons
b. cellular respiration is a catabolic process
113
Glucose can be obtained from:
a. glycogenolysis
b. fatty acid hydrolysis
c. protein anabolism
d. ketogenesis
a. glycogenolysis
114
