Gropper - Carbohydrates Flashcards
The majority of energy in the typical American diet comes from ____.
(A) fat
(B) protein
(C) carbohydrate
(D) vitamins
(C) carbohydrate
A ketopentose is a carbohydrate containing ____.
(A) five carbons and a ketone group
(B) six carbons and an aldehyde group
(C) three carbons and an aldehyde group
(D) seven carbons and a ketone group
(A) five carbons and a ketone group
What type of bond holds two monosaccharides together?
(A) ionic
(B) hydrogen
(C) covalent
(D) peptide
(C) covalent
When compounds with one or more chiral carbon atoms and the same formula are arranged as mirror images they are said to be ____.
(A) symmetrical
(B) enantiomers
(C) rotated
(D) linear
(B) enantiomers
Name the model that depicts cyclized monosaccharides as lying in a horizontal plane with the hydroxyl groups pointing down or up from the plane.
(A) Haworth
(B) Fischer projection
(C) cyclized Fischer projection
(D) stereoisomer
(A) Haworth
What are the major dietary energy sources that are composed of two simple sugars?
(A) disaccharides
(B) polysaccharides
(C) monosaccharides
(D) trioses
(A) disaccharides
What is the most common digestible homopolysaccharide existing as both amylose and amylopectin?
(A) glycogen
(B) cellulose
(C) hemicellulose
(D) starch
(D) starch
Which of the following homopolysaccharides made of glucose contributes the most energy to the ordinary diet?
(A) amylose
(B) amylopectin
(C) glycogen
(D) cellulose
(B) amylopectin
A homopolysaccharide that is important in human diets is ____ and the end product formed from the complete digestion of this homopolysaccharide is ____.
(A) cellulose; glucose
(B) lactose; galactose
(C) glycogen; glucose
(D) starch; glucose
(D) starch; glucose
Which disaccharide is commonly found in mushrooms?
(A) glucose
(B) fructose
(C) trehalose
(D) galactose
(C) trehalose
What is the key enzyme in digestion of polysaccharides?
(A) starch amylopectin
(B) β-amylase
(C) α-dextranase
(D) α-amylase
(D) α-amylase
Cellulose is a polymer of glucose where the monomers are connected by β-linkages. Humans cannot digest this substance because ____.
(A) they only produce α-amylase
(B) they produce insufficient quantities of β-amylase
(C) cellulose is resistant to the human form of β-amylase (D) the β-linkages are too strong to be hydrolyzed
(A) they only produce α-amylase
Chiral carbon atoms have ____.
(A) four hydrogens attached to them
(B) two methyl groups and two hydrogens attached to them
(C) three hydrogen atoms and one methyl group attached to them
(D) four different atoms or groups attached to them
(D) four different atoms or groups attached to them
The enzyme needed to hydrolyze the α (1,6) bond of amylopectin is ____, which is secreted by the ____.
(A) amylase; enterocyte
(B) sucrose; pancreas
(C) lactase; enterocyte
(D) isomaltase; enterocyte
(D) isomaltase; enterocyte
The disaccharidases are synthesized by the ____.
(A) pancreas
(B) liver
(C) enterocyte
(D) chief cell
(C) enterocyte
Sucrose digestion is initiated in the ____.
(A) pylorus
(B) fundus
(C) duodenum
(D) mouth
(C) duodenum
Starches in the duodenum and jejunum are acted upon by ____.
(A) β-amylase
(B) lipase
(C) sucrase
(D) α-amylase
(D) α-amylase
α-dextrinase is also called ____.
(A) β-amylase
(B) isomaltase
(C) α-amylase
(D) lactase
(B) isomaltase
Choose the best description of the main method of glucose absorption.
(A) passive diffusion down a concentration gradient
(B) active transport with fructose
(C) facilitated transport
(D) active transport with sodium
(D) active transport with sodium
Which sugar is not present in the systemic circulation due to efficient removal by the liver?
(A) glucose
(B) fructose
(C) galactose
(D) sucrose
(B) fructose
The glucose transporter that is sensitive to insulin is ____.
(A) GLUT1
(B) GLUT2
(C) GLUT4
(D) SGLT1
(B) GLUT2
Which hormonal changes occur in response to a fall in blood glucose concentration?
(A) increased insulin, decreased glucagon
(B) decreased insulin, increased glucagon
(C) decreased insulin, decreased glucocorticoids
(D) increased insulin, increased glucagon
(B) decreased insulin, increased glucagon
Glycemic load considers the ____ in the food.
(A) protein and carbohydrate content
(B) fat and carbohydrate content
(C) fat to carbohydrate ratio
(D) quantity and quality of carbohydrate
(D) quantity and quality of carbohydrate
People with type 1 diabetes have ____.
(A) slow translocation of GLUT4 receptors from the Golgi body
(B) lack of mRNA synthesis for GLUT4 receptors in adipocytes or myocytes
(C) increased glycogenesis in myocytes after a meal
(D) below-normal glucokinase activity because of low insulin levels
(D) below-normal glucokinase activity because of low insulin levels
Insulin is an anabolic hormone. Which process does insulin stimulate?
(A) lipolysis
(B) gluconeogenesis
(C) glycogenesis
(D) ketogenesis
(C) glycogenesis
Glucose phosphorylation in the liver is catalyzed by ____.
(A) glucokinase
(B) hexokinase
(C) insulin
(D) glucagon
(A) glucokinase
Due to a lack of the enzyme glucose-6-phosphatase, which tissue capable of glycogenesis cannot contribute to blood glucose levels between meals?
(A) liver
(B) muscle
(C) brain
(D) kidney
(B) muscle
Glycolysis is a process involving ____.
(A) synthesis of fatty acids
(B) reactions that convert glucose to glycogen
(C) reactions that convert glucose to pyruvate
(D) reactions that convert glycogen to protein
(C) reactions that convert glucose to pyruvate