Chapter 3 Objectives

Question 0

Cell Membrane

Answer 0

Sometimes called the plasma membrane, the membrane sparates the cell from its external environment and from the neighboring cells. It also regulates the passage or transport of certain molecules into and out of the cell, while preventing the passage of others.

Question 1

Three major regions of the cell

Answer 1

Cell Membrane, Nucleus and Cytoplasm

Question 2

Nucleus

Answer 2

Most important organelle, it’s two vital functions are to control activities of the cell and facilitate cel division.

Question 3

Cytoplasm

Answer 3

sticky, semifluid material found between the nucleus and the membrane. consists of proteins, lipids, carbohydrates, minerals, salts and water.

Question 4

Chemical composition of the plasma membrane

Answer 4

Made of a double layer of lipids (phospholipids, cholesterol and so on) within which proteins are embedded.

Question 5

Structure and Function of Tight Junctions

Answer 5

They are Impermeable, made up of integral proteins. They hold cells together.

Question 6

Structure and Function of Desmosomes

Answer 6

Found in areas of high stress, common in epithelia. Anchoring Junction

Question 7

Structure and Function of Gap Junctions

Answer 7

Allow for cell to cell communication

Question 8

Simple Diffusion

Answer 8

in simple diffusion, non polar and lipid soluble substances diffuse directly thought the lipid bilayer. such substances include oxygen, carbon dioxide and fat-soluble vitamins.

Question 9

Facilitated Diffusion

Answer 9

Certain molecules, notably glucose and other sugars, some amino acids and ions are transported passively even though they are unable to pass through the lipid bilayer. Instead they move through the membrane by a passive transport process called facilitated diffusion in which the transported substance either binds to protein carriers in the membrane and is ferried across or moves through water filled protein channels.

Question 10

Osmosis

Answer 10

The diffusion of a solvent, such as water, through a selectively permeable membrane is osmosis. Even though water is highly polar, it passes via osmosis through the lipid bilayer.

Question 11

Primary Active Transport

Answer 11

a type of active transport in which the energy needed to drive the transport process is provided directly by hydrolysis of ATP

Question 12

Secondary Active Transport

Answer 12

Form of active transport across a biological membrane in which a transporter protein couples the movement of an ion down its electrochemical gradient to the uphill movement of another molecule or ion against a concentration gradient.

Question 13

Endocytosis

Answer 13

means by which fairly large extracellular molecules or particles enter cells.

Question 14

Exocytosis

Answer 14

Mechanism by which substances are moved from the cell interior to the extracellular space as a secretory vesicle fuses with the plasma membrane.

Question 15

Pinocytosis

Answer 15

engulfing of extracellular fluid by cells

Question 16

phagocytosis

Answer 16

Engulfing of foreign solids by cells.

Question 17

Receptor-mediated endocytosis

Answer 17

The type of endocytosis in which engulfed particles attach to receptors before endocytosis occurs.

Question 18

composition of cytosol

Answer 18

(fluid that contains the organelles) it is a complex mixture of substances dissolved in water. Although water forms the large majority of the cytosol, its structure and proerties within cells is not well understood.

Question 19

Function of Lysosomes

Answer 19

to remove waste, they digest excess or worn out organelles, food particles and engulfed viruses or bacteria

Question 20

Function of peroxisomes

Answer 20

lipid metabolism and chemical detoxification. They also carry out oxidation reactions that break down fatty acids and amino acids.

Question 21

Structure and function of cytoskeletal elements

Answer 21

responsible for cell shape, movement and motility of organelles within a cell.

Question 22

Cell junctions that are important in cell communication are _____

Answer 22

gap junctions

Question 23

Which structures are fingerlike projections that greatly increase the absorbing surface of cells?

Answer 23

Microvilli

Question 24

DNA is replicated during which stage of interphase?

Answer 24

S phase

Question 25

Mitosis is the division of the ________

Answer 25

nucleus

Question 26

Cytokinesis is defined as ________

Answer 26

the division of the cytoplasm

Question 27

The ________contains both an anticodon and an amino acid

Answer 27

tRNA

Question 28

In which stage of mitosis do the identical sets of chromosomes uncoil and resume their chromatin form?

Answer 28

Telophase

Question 29

In areas of the body subject to a higher degree of mechanical stress, which of the following types of membrane junctions would you expect to most prevalent?

Answer 29

Desmosomes

Question 30

DNA is _______ to RNA, which is then ________ to protein.

Answer 30

Transcribed; translated

Question 31

In order for the DNA molecule to get “short and fat” to become a chromosome, it must first wrap around small molecules called_______.

Answer 31

histones

Question 32

How is active transport different from facilitated diffusion?

Answer 32

it moves against the concentration gradient

Question 33

ATP, the energy source for cells is produced in the

Answer 33

Mitochondria