Final Exam Study Guide NDFS 434

Enzymes of which metabolic pathway can be found in the cytoplasmic matrix?

Glycolysis

Where are the majority of the components of the electron transport chain embedded?

Mitochondrial inner membrane

What is the major route for ATP production in the cell?

Oxidative phosphorylation

What is the smooth endoplasmic reticulum (SER) associated with?

lipid synthesis

Membrane lipid bilayers consist primarily of what?

phospholipids

Which cells produce amylase?

Pancreatic exocrine cells and salivary glands

What is one action of gastrin?

Stimulates chief cells to produce pepsinogen

Which cells, found in the stomach, secrete hydrochloric acid and intrinsic factor?

parietal cells

Which phrase best describes the function of the crypts of Lieberkühn?

cellular differentiation

What is the hormone primarily responsible for contraction of the gallbladder and release of bile into the duodenum?

Cholecytokinin (CCK)

What might be the result of large gallstone blocking the cystic duct and causing cholestasis?

Interference with fat digestion

In which metabolic pathway does pyruvate carboxylase play a role?

Gluconeogenesis

What is the major site of expression for the monosaccharide transporter GLUT4?

skeletal muscle and adipose tissue

Cellulose is a polymer of glucose linked through beta linkages. Humans cannot digest it because..?

They only produce alpha-amylase

What enzyme hydrolyzes the alpha (1,6) bound in amylopectin?

Alpha-limit dextrose

Glycemic load, which is different than glycemic index, considers the .... in food?

quantity of carbohydrate

What mechanism is most often utilized by ATP, ADP, and AMP to regulate metabolism?

Allosteric modulation

Which substance is converted into glycogen in the process of glycogenesis?

glucose-6-phosphate

Which component of grain contains the most fiber?

bran

Describe lignin

The main noncarbohydrate component of fiber and a polymer of phenol. Found in carrots, berries, and wheat, and insoluble in water.

Describe hemicellulose

Contains a number of sugars in its backbone and side chains. Some are water soluble and some are insoluble; found in bran and whole grains.

What is a predominant source of chitin?

shells of crab, lobster, and shrimp

What are good sources of beta-glucans in the diet?

oat products and barley

Where does fermentation of fiber mostly occur?

proximal/ascending colon

What is not targeted fro restriction in the low-FODMAP diet?

Maltose

Describe gums

Hydrocolloids

What enzyme creates a double bond in a fatty acid?

desaturase

Which enzyme removes triacylglycerol from plasma?

lipoprotein lipase

What is the rate-limiting enzyme in cholesterol synthesis?

HMG-CoA reductase

In which cells would we find the highest concentration of sphingoliipids?

Central nervous system

What is true about phospholipids?

They are amphipathic in nature

List the molecules found in a micelle

Linolenic acid, 2-monoacylglycerols, cholesterol, fat-soluble vitamins

What is the correct sequential order for participants in lipid digestion?

bile, colipase, pancreatic lipase, micelles

What does the liver synthesize to transport endogenous triacylglycerol?

VLDLs

Which apolipoprotein is key to the delivery of triacylglycerol to tissues by the chylomicrons?

ApoC-2

Which lipoprotein is not normally present in blood in the fasting state?

Chylomicrons

The interaction between a receptor and what component is key to the hepatocyte's internalization of LDL?

Apolipoprotein B-100

Which drug therapy is associated with reduced cholesterol synthesis in the liver?

HMG-CoA reductase inhibitors

What is the end product of beta-oxidation of a fatty acid?

acetyl-CoA

Ketones are produced from...?

Acetyl CoA

What is the end product of the fatty acid synthase system?

palmitate

In addition to the endocrine cells that secrete insulin and glucagon, what other type of active tissue is found in the pancreas?

Exocrine cells that produce digestive enzymes

Bile salts are synthesized from cholesterol in the...?

liver

In which metabolic pathway do branching enzymes play a key role?

Glycogenesis

What is the name of the protein that is used to form the initial glycogen primer?

Glycogenin

Which glucose transporter is sensitive to insulin?

GLUT4

What is true of carbon-carbon double bonds in the trans configuration in fatty acids?

It extends the fatty acid into a linear shape

What are chemical messengers secreted by endocrine tissue and transported to target organs where they regulate metabolic processes?

hormones

What binds to nutrients and regulates theier circulation and their flow into and out of cells?

transport proteins

What are catalysts that change the rate of reactions occurring in the body?

enzymes

What are fibrous and contractile proteins found in bone, teeth, skin, muscles, blood vessels, and hair?

structural proteins

What is a precursor for the amino acid tyrosine?

Phenylalanine

What are the precursors for the amino acid glutamine?

glutamate and ammonia

A gene mutation that results in phenylketonuria (PKU) effects which enzyme?

Phenylalanine hydroxylase

Which of the following activation processes is not true?

Trypsin activates chyotrypsinogen

Chymotrypsin activates trypsinogen

Trypsin activates procarbosypeptidases

Enteropeptidase activates trypsinogen

Chymotrypsin activates trypsinogen

What statement is true about the absorption of protein?

The majority of amino acids are absorbed as peptides

Which non-protein compound is found primarily in muscle and acts as a storehouse for high energy phosphate?

creatine

All of the following are effects of insulin on protein synthesis except:

insulin promotes uptake of amino acids

insulin stimulates movement of amino acid transporters to the cell membrane

insulin stimulates use of amino acids for energy

insulin inhibits enzymes responsible for degradation of amino acids

Insulin stimulates use of amino acids for energy

What percent loss of lean body mass is associated with decreased immunity, increased infection risk, and 10% mortality risk

10%

What tissue stores large amounts of triacylglycerols?

Adipose tissue

Which regulatory hormone stimulates liver glycogenolysis and gluconeogenesis?

Glucagon

Which regulatory hormone stimulates removal of glucose from the blood and anabolic reactions?

insulin

What are the two compounds that connect the metabolic pathways of carbohydrates, lipids, and proteins?

pyruvate and acetyl-CoA

What is a regulated enzyme (an enzyme modulating a non-reversible reaction) in glycolysis?

phosphofructokinase

Where does most of the fatty acid synthesis occur in humans?

liver

In which state does a protein-sparing shift in metabolism from gluconeogensis to lipolysis occur?

starvation state

In which organ does urea synthesis occur?

Liver

An individual who has not eaten in five days will most likely have an elevated level of which hormone?

glucagon

Which hormone has the primary responsibility for directing energy metabolism in the fed state?

insulin

What is the preferred source of energy used by muscles to spare protein during prolonged starvation (>2 days)?

ketones

What describes the lactic acid system?

anaerobic glycolysis

What components of the diet provide the majority of energy for ATP production?

lipid and carbohydrate

Following a carbohydrate-rich meal, skeletal and cardiac muscles express which protein on their cell surfaces?

GLUT4

When glucose exceeds the glycogen storage capacity of the liver, what is the excess glucose converted to?

fatty acids and triacylglycerols

What provides the majority of blood glucose during the postabsorptive state?

hepatic glycogenolysis

The generally accepted respiratory quoteint (RQ) value for carbohydrate is...?

1.0

The thermic effect of food represents the..?

increase in energy expenditure associated with the body's processing of food

Which RQ would not be possible for an ordinary mixed diet of carbohydrate protein, and fat?

0.85

0.80

0.75

0.15

0.15

Which hormone increases the urge to eat?

Ghrelin

Where is insulin produced?

beta cells of the pancreas

Where is leptin produced?

white adipose tissue

A person with a BMI of 31 would fall into what category?

obese

A primary function of vitamin C is to act as what?

antioxidant

What is a major role of thiamin?

energy production

Beriberi is a deficiency of which vitamin?

thiamin

Riboflavin is found most often in what types of food?

milk and milk products

When the diet is adequate in protein, the body can synthesize niacin from which amino acid?

Tryptophan

Which of the water-soluble vitamins is found widely distributed in all plant and animal foods, which makes a deficiency unlikely?

pantothenic acid

Which vitamin deficiency results in megaloblastic anemia?

folate

Folate is vitally important for dividing cells during growth because of its essential role in the synthesis of what?

purines and pyrimidines

Intrinsic factor is required for the majority of absorption of which vitamin?

B12

What binds to antigens and inactivates them or causes them to be destroyed?

immunoproteins

When the amino group has been removed from an amino acid, the carbon skeleton or alpha-keto acid may be used in many different ways. Which of the following is not a possible fate for the carbon skeleton?

conversion to glucose

oxidation for energy

synthesis of ketones

synthesis of creatine

synthesis of creatine

What is a nitrogen-containing, nonprotein compound that fucntions as a major antioxidant in cells and plasma?

glutamine

Which process is NOT a source of ammonia in the body?

urea formation in the liver

deamination of amide groups from glutamine

degradation of pyrimidines

metabolism of amino acids

urea formation in the liver