Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biochemistry- 1 > Midterm 2: Digestion > Flashcards

Midterm 2: Digestion Flashcards

1
Q

Digestion is a form of ___________

A

catabolism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

A hydrolytic process

A

breaks down large food molecules (carbohydrates, proteins, lipids) into smaller ones (monosaccharides, amino acids, fatty acids)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Path of the digestive tract:

A

mouth–> esophagus–> stomach–> small intestine–> large intestine (colon)–> rectum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What other organs are involved in digestion?

A

pancreas, gallbladder, liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

True/False: Most of our supply of carbohydrates (i.e., glucose) is obtained through our diet.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Can our body synthesize glucose? If so, how?

A

gluconeogenesis; amino acids, pyruvate, and lactate can be used to synthesize glucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the building blocks of carbohydrates?

A

Monosaccharides (simple carbs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What type of bonds join monosaccharides together?

A

glycosidic bonds (covalent bonds) form disaccharides and polysaccharides (complex carbs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Monosaccharides include:

A

glucose, galactose, and fructose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Disaccharides include:

A

lactose, maltose, sucrose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Polysaccharides include:

A

glycogen, starch, cellulose, and GAGs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Where does carbohydrate digestion begin?

A

mouth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What enzyme is contained in saliva? What does it break down? How?

A

salivary amylase (Enzyme) that hydrolyzes 5% of starch in the mouth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Amylase breaks down starch into what two components?

A

maltose and a polysaccharide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Salivary amylase is inactivated by what?

A

the acidity of the stomach

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

(Minimal/maximum) carbohydrate digestion occurs in the stomach?

A

Minimal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

After digestion occurs in the stomach, carbohydrate digestion continues where?

A

in the lumen of the small intestine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What two components are secreted from the pancreas into the small intestine for carb digestion?

A

Bicarbonate (HCO3-) and amylase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is bicarbonate?

A

It is a buffer that neutralizes acidic stomach contents in the small intestine (secreted by the pancreas)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Pancreatic amylase has what function?

A

It hydrolyzes disaccharides and complex carbs into monosaccharides in the small intestine (secreted by the pancreas)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What enzymes are secreted by the small intestine, aiding in carb digestion?

A

Disaccharidases (lactase, sucrase, maltase) are secreted from the small intestines

Hydrolyze disaccharides into monosaccharides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

At the end of carbohydrate digestion in the small intestine, what have the carbs become?

A

~80% of monosaccharides are glucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

After carb digestion occurs in the small intestine, the monosaccharides go where?

A

they are absorbed into enterocytes (small intestine cells) of the intestinal mucosa to reach blood capillaries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

How do the monosaccharides enter enterocytes?

A

Substances cannot pass between epithelial cells because these cells are bound by tight junctions, so they enter enterocytes by co-transport and facilitated diffusion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What uses movement of 1 molecule through the cell membrane from higher to lower concentration to power the movement of another from lower to higher concentration?

A

Co-transport

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What uses the movement of substances from an area of higher to an area of lower concentration using a carrier protein in the cell membrane?

A

facilitated diffusion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

After entering blood capillaries, monosaccharides are transported to where? Pathway?

A

the liver via the hepatic portal vein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What 3 things occur here (in the liver with carb digestion)?

A

Galactose is primarily converted to glucose

Fructose is primarily converted to glucose and lactate

Glucose is stored as glycogen or transported to peripheral tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

How is glucose stored in the liver?

A

glucose is stored as glycogen or transported to peripheral tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Glycogen is used to maintain blood glucose levels at _________________ mg/dL.

A

70-100 mg/dL

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

In the peripheral tissues of the liver, glucose is used for

A

energy production or stored as glycogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

When liver cells and peripheral tissue are saturated with glycogen, what happens?

A

excess glucose is converted into fatty acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Where are undigested carbohydrates (fiber) eliminated?

A

by the colon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What cannot be digested by humans?

A

Dietary fiber is from plant cell walls (i.e., cellulose) and is resistant to human digestive enzymes; Unable to be digested and absorbed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

How are undigested carbs classified?

A

insoluble or soluble

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Insoluble fiber passes through the digestive tract relatively untouched, why?

A

Speeds up digestion; Adds bulk to stool so it can pass easier

37
Q

Soluble fiber forms a gel when mixed with water in the digestive tract, what does this do?

A

Slows down digestion and absorption of glucose, thereby preventing blood glucose spikes
Fermented by colon bacteria into short-chain fatty acids and gases

38
Q

Why do some amino acids have to be obtained from our diet?

A

Because our body cannot synthesize them

39
Q

Essential amino acids include the following:

A

histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine
PLT HI LMTV (lets move to Venice)

40
Q

What are the building blocks of proteins?

A

Amino acids

41
Q

• Amino acids are joined together by what type of bond? Forming?

A

in a peptide bond to form peptides and polypeptides (proteins)

42
Q

Peptides and polypeptides take on a 3-D shape through various bonds:

A 
Hydrogen bonds
Ionic bonds
van der Waals interactions
Hydrophobic interactions
Disulfide bridges
43
Q

Where does digestion begin for proteins?

A

Digestion begins in the stomach

44
Q

What denatures proteins in the stomach?

A

Stomach acid

45
Q

What hydrolyzes peptide bonds?

A

Pepsin

46
Q

After leaving the stomach, where does protein digestion continue?

A

in the lumen of the small intestine

47
Q

Bicarbonate (HCO3-), trypsin, chymotrypsin, and carboxypeptidase are secreted from where? To help digest what?

A

the pancreas into the small intestine; protein

48
Q

What is the role of bicarbonate in protein digestion?

A

it is a buffer that neutralizes acidic stomach contents

49
Q

What is the role of Trypsin, chymotrypsin, carboxypeptidase in protein digestion?

A

hydrolyze peptide bond

50
Q

What are secreted from the small intestine in protein digestion? What is their role?

A

Peptidases; Hydrolyze peptides into amino acids

51
Q

Amino acids are then absorbed into enterocytes of the intestinal mucosa to reach blood capillaries, Is this the same thing that occurs with carb digestion?

A

YES!

52
Q

Substances cannot pass between epithelial cells because of??

A

tight junctions

53
Q

How do amino acids enter enterocytes?

A

by co-transport

54
Q

Once in the blood capillaries, monosaccharides are transported to the liver via the _____________
Used for protein synthesis, converted into _________, converted into __________, or transported to peripheral tissues for protein synthesis

A

hepatic portal vein; glucose; fatty acids

55
Q

Small amount of protein is eliminated by _______.

A

the colon

56
Q

Are lipids synthesized or obtained through our diet?

A

BOTH: they can either be synthesized or obtained through our diet

57
Q

How are lipids classified?

A

due to their hydrophobicity

58
Q

What does hydrophobicity mean?

A

Do not dissolve in water; Cluster together away from water (form fat globules)

59
Q

Lipids are which three?

A

triacylglycerol (triglyceride, TAG), cholesterol, phospholipids

60
Q

TAG is composed of __________.

A

3 fatty acids + glycerol (a sugar) and comprises 90% of dietary lipids

61
Q

Phospholipids are composed of ___________.

A

2 fatty acids + Glycerol + Phosphate + 1 of 4 polar groups

62
Q

Cholesterol is composed of ___________.

A

a steroid core of 4 fused rings + side chains

63
Q

Does any digestion for lipids occur in the mouth or stomach?

A

Limited digestion occurs in the mouth and stomach

Lingual lipases and gastric lipases hydrolyze fatty acids with ≤12 carbons

64
Q

Fat globules leave the stomach and enter the ___________.

A

small intestine

65
Q

__________ are secreted from the gallbladder (synthesized in the liver from cholesterol) into the small intestine. (lipid digestion)

A

Bile salts

66
Q

Amphipathic molecules that emulsify fat globules (surround pieces of fat globules and break them into smaller droplets)

A

Bile Salts

67
Q

What is the function of bile salts?

A

Increases the surface area of lipids and makes them more accessible to digestive enzymes

68
Q

_____________ are secreted from the pancreas into the small intestine (lipid digestion)

A

Bicarbonate (HCO3-) and lipases

69
Q

___________ is a buffer that neutralizes acidic stomach contents

A

Bicarbonate

70
Q

Pancreatic lipase hydrolyzes triglycerides into ___________.

A

monoglyceride and (2) free fatty acids

71
Q

Bile salts continue to surround fat droplets forming ____________ ?

A

micelles

72
Q

What are micelles?

A

They are a core of lipids (hydrophobic regions inside and hydrophilic regions outside) surrounded by bile salts

73
Q

Transport lipids through the intestinal lumen to the epithelial lining

A

Bile salts that surround fat droplets forming micelles

74
Q

Once micelles reach the epithelial lining of the small intestine, where are they are then absorbed?

A

into enterocytes

75
Q

How do Micelles enter enterocytes?

A

by simple diffusion

76
Q

movement of substances from an area of higher concentration to an area of lower concentration,

A

Simple diffusion

77
Q

Where are Bile salts are absorbed?

A

in the more distal small intestine and transported back to the liver through the portal vein

78
Q

Once inside the enterocyte, _______ is reformed and packaged into ____________, along with other lipids

A

TAG; chylomicrons

79
Q

__________ are a core of lipids (hydrophobic regions inside and hydrophilic regions outside) surrounded by lipoproteins

A

Chylomicrons

80
Q

Transport lipids through the bloodstream from the __________ to the ____________.

A

intestine to the liver

81
Q

Chylomicrons enter____________, bypassing blood capillaries. Why?

A

lymph capillaries; Chylomicrons are too LARGE to enter blood capillaries directly

82
Q

Lipid process through blood?

A

Lymph → Veins → Arteries → Blood capillaries

83
Q

Within blood capillaries, _________ are digested.

__________ hydrolyzes triglycerides into fatty acids and glycerol.

Glycerol returns to the __________ to be reused.

Fatty acids enter cells to be used as an energy source or stored as __________ (if entering adipose tissue).

Chylomicron remnants are transported to the liver.

A

chylomicrons

Lipoprotein lipase

liver

TAG

84
Q

In the liver, chylomicron remnants are recycled and TAG is reformed

TAG, along with other lipids (mainly ___________), is packaged into _______ for transport through the bloodstream to tissues

The structure of ________is similar to chylomicrons and allows transport of lipids between tissues in an ________ environment

A

cholesterol

VLDL

VLDL

aqueous

85
Q

Within blood capillaries, what is digested? (lipid)

A

VLDL is digested

86
Q

Loss of triglycerides and some apoproteins

converts _________ to __________

A

VLDL into LDL (low density lipoprotein)

87
Q

LDL is an important carrier of __________ to tissues

A

cholesterol

88
Q

Cholesterol can be deposited in the cell membrane, used to make what?

A

Vitamin D, bile acid or steroid hormones

89
Q

_______________ carries excess cholesterol away from tissues to the liver

A

HDL (high density lipoprotein)

Biochemistry- 1 (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions