Chapter 2 - Guyton

Question 1

Water composes how much of the cell?

Answer 1

70-85%

Question 2

What is the main structural difference between structural proteins and functional proteins?

Answer 2

structural - composed mainly of long filaments; functional - tubular-globular form

Question 3

What is the significance of carbohydrate to the cell?

Answer 3

little function structurally except as part of glycoprotein but plays a major role in nutrition for the cell

Question 4

Which type of proteins (integral or peripheral) are the majority of glycoproteins?

Answer 4

integral

Question 5

The carbohydrates on the glycocalyx have what charge?

Answer 5

negative (repel other substances)

Question 6

How does cholesterol contribute to the membranes structurally?

Answer 6

decreases fluidity and permeability while increasing flexibility and stability

Question 7

Which organelle is similar to (and contiguous with) the plasma membrane?

Answer 7

ER

Question 8

Pathway of newly formed substances to exit cell.

Answer 8

granular ER–>smooth ER–>transport vesicles–>Golgi apparatus–>secretory vesicles–>exit cell membrane

Question 9

What happens to proteins when they are “processed”?

Answer 9

crosslinked, folded, glycosylated (N-linked), cleaved

Question 10

What is synthesized in the smooth ER?

Answer 10

lipids (phospholipids and cholesterol)

Question 11

General characteristics of Golgi apparatus.

Answer 11

membrane composition similar to that of the smooth ER and plasma membrane, composed of 4 or more stacked layers of flat vesicular structures

Question 12

What occurs at the Golgi apparatus?

Answer 12

receives transport vesicles from the smooth ER, substances formed in the ER are phosporylated and glycosylated, substances are concentrated, sorted, and packaged for secretion

Question 13

What occurs during exocytosis?

Answer 13

secretory vesicles diffuse through the cytosol and fuse to the plasma membrane, lysosomes fuse with internal endocytotic vesicles

Question 14

What occurs during secretion?

Answer 14

secretory vesicles containing proteins synthesized in the RER bud from the Golgi apparatus, fuse with plasma membrane to release contents

Question 15

What are the two types of secretion?

Answer 15

constitutive (random) and stimulated (trigger)

Question 16

Lysosomes

Answer 16

vesicular organelle formed from budding Golgi, contain hydrolytic enzymes, fuse with pinocytotic or phagocytotic vesicles to form digestive vesicles

Question 17

What occurs during lysosomal storage diseases?

Answer 17

absence of one or more hydrolases (not synthesized, inactive, not properly stored and packaged), so lysosomes become engorged with undigested substrate

Question 18

Examples of lysosomal storage diseases.

Answer 18

acid lipase A deficiency, I-cell disease (non-specific), Tay-Sachs disease (HEX A)

Question 19

Peroxisomes

Answer 19

similar physically to lysosomes, two major differences are formed by self-replication and they contain oxidases, function is to oxidize substances that may be otherwise poisonous (alcohol)

Question 20

The vesicular membrane of which organelle continuously replaces the cell membrane after it forms phagocytotic or pinocytotic vesicles.

Answer 20

Golgi apparatus

Question 21

Energy from ATP is used to promote three major categories of cellular functions:

Answer 21

1) transport of substances through multiple membranes in the cell;
2) synthesis of chemical
compounds throughout the cell;
3) mechanical work

Question 22

The double nuclear membrane and matrix are contiguous with the ____________ ___________.

Answer 22

ER

Question 23

What is found in the nucleoplasm?

Answer 23

chromatin (condensed DNA)

Question 24

General characteristics of the nucleolus.

Answer 24

one or more per nucleus, contains RNA and proteins, not membrane delimited, functions to form the granular subunits of ribosomes

Question 25

Receptor-mediated endocytosis

Answer 25

molecules attach to cell-surface receptors concentrated in clathrin-coated pits, receptor binding induces invagination, also ATP-dependent and involves recruitment of actin and myosin

Question 26

A maximum of how many aTP are formed per molecule of glucose degraded.

Answer 26

38

Question 27

During ATP production, glucose from carbohydrates, amino acids from protein, and fatty acids from fats are converted into what?

Answer 27

acetyl CoA

Question 28

Two locations in the body cilia.

Answer 28

inside surfaces of the human airway and fallopian tubes

Question 29

Composition of each cilium.

Answer 29

11 microtubules (9 double tubules, 2 single tubules), each cilium is an outgrowth of the basal body and is covered by an outcropping of the plasma membrane

Question 30

Ciliary movement is dependent on what?

Answer 30

ATP and also calcium and magnesium

Question 31

Ameboid locomotion

Answer 31

continual endocytosis at the “tail” and exocytosis at the leading edge of pseudopodium, attachment of pseudopodium is facilitated by receptor proteins carried by vesicles, forward movement results through interaction of actin and myosin (ATP-dependent)

Question 32

What is chemotaxis?

Answer 32

most important factor in controlling ameboid movement, either move toward the
source of a chemotactic substance (positive chemotaxis) some cells move away from the source (negative chemotaxis)

Question 33

The only means by which large macromolecules can enter the cell?

Answer 33

pinocytosis

Question 34

Only certain cells have the capability to perform this function and it involves particles rather than the macromolecules such as in pinocytosis.

Answer 34

phagocytosis