Chapter 3

Question 1

Osmosis

Answer 1

The diffusion of water molecules through a selectively permeable membrane from one region to another.

Question 2

Plasma Membrane

Answer 2

The outer boundary of a cell that is selectively permeable. phospholipid bilayer, which proteins are suspended.

Question 3

Nucleus

Answer 3

The dense center of an atom, composed of protons and neutrons. Control center.

Question 4

Mitosis

Answer 4

four-step process that creates new cells

Question 5

Adipose cells

Answer 5

Insulate and protect underlying cells and store energy

Shapeless, clumped

Question 6

Epithelial cells

Answer 6

Protect underlying cells in skin and organs

Flat, tightly packed

Question 7

Muscle cells

Answer 7

Contract and pull structures closer together

Thin, rod-like

Question 8

Nerve cells

Answer 8

Transmit nerve impulses from one part of the body to another

Long, threadlike

Question 9

The cytoplasm

Answer 9

is a fluid that surrounds and moves around the nucleus

Question 10

Selective permeability

Answer 10

The selective process the body uses to allow or refuse the entry of bodily fluids into and out of cells.

Question 11

Organelles

Answer 11

In the cytoplasm provide the power, cleaning capability, and building blocks for replicating and maintaining the cell.

Question 12

Lysosomes

Answer 12

Destroy an transport waste from the cell.

Question 13

Mitochondria

Answer 13

Release energy from nutrients and convert it into usable energy for the cell’s work.

Question 14

Ribosomes

Answer 14

Protein particles and RNA that help the cell build proteins.

Question 15

Endoplasmic reticulum

Answer 15

A double-walled membrane network inside a cytoplasm.

Question 16

Cell division

Answer 16

The process of a single cell splitting into two daughter cells, each with genetic material that is identical to the original cell.

Question 17

Interphase

Answer 17

Cell grows and maintains its function; for cells that divide duplicates genetic material

Question 18

Mitosis

Answer 18

This is the period of cell division in non-sex cells

Question 19

Cyptoplasmic division

Answer 19

The cell elongates and muscle like filaments pinch the cell in two after mitosis is complete

Question 20

Telomeres

Answer 20

DNA located at the tips of chromosomes; physically control the number of times a cell will divide.

Question 21

Prophase

Answer 21

In prophase, chromatin condenses into short dense rods called chromosomes for easier distribution to daughter cells.

Question 22

Metaphase

Answer 22

In metaphase, chromosomes line up along the center of the cell.

Question 23

Anaphase

Answer 23

In anaphase, each centromere divides, and chromatids separate from each other.

Question 24

Telophase

Answer 24

In telophase, chromosomes cluster on each side of the cell.

Question 25

Chromatin

Answer 25

Nucleic acids and proteins in the cell nucleus that stain readily with basic dyes and condense to form chromosomes during cell division.

Question 26

Osmotic Pressure

Answer 26

the force required to prevent the movement of water across a selectively permeable membrane. Force that pulls water across the plasma membrane

Question 27

Light microscope

Answer 27

allow us to visualize the general features of cells.

Question 28

Electron microscopes

Answer 28

allow us to visualize the fine structure of cells.

Question 29

Lipids

Answer 29

give the plasma membrane most of its structure and some of its function.

Question 30

Transport proteins

Answer 30

include channel proteins, carrier proteins, and ATP-powered pumps

Question 31

Receptor proteins

Answer 31

are linked to and control channel proteins.

Question 32

Membrane proteins

Answer 32

function as marker molecules, attachment proteins, transport proteins, receptor proteins, and enzymes.

Question 33

Lipid-soluble molecules

Answer 33

pass through the plasma membrane readily by dissolving in the lipid bilayer.

Question 34

Large, non-lipid-soluble molecules and ions (e.g., glucose and aminoacids)

Answer 34

are transported through the membrane by transport proteins.

Question 35

Vesticles

Answer 35

Large, non-lipid-soluble molecules, as well as very large molecules and even whole cells, can be transported across the membrane in vesicles.

Question 36

Diffusion

Answer 36

is the movement of a substance from an area of higher solute concentration to one of lower solute concentration (down a concentration gradient). uniform distribution of molecules. No energy

Question 37

The concentration gradient

Answer 37

is the difference in solute concentration between two points divided by the distance separating the points.

Question 38

The rate of diffusion

Answer 38

increases with an increase in the concentration gradient, an increase in temperature, a decrease in molecular size, and a decrease in viscosity.

Question 39

Isosmotic solutions and

Answer 39

have the same concentration of solute particles - cells neither sink nor swell

Question 40

hyperosmotic solutions

Answer 40

have a greater concentration of solute particles - shrink or crenate

Question 41

hyposmotic solutions

Answer 41

have a lower concentration of solute particles - swell or lysis

Question 42

Mediated transport

Answer 42

is the movement of a substance across a membrane by means of a transport protein. The substances transported tend to be large, water-soluble molecules.

Question 43

Facilitated diffusion

Answer 43

moves substances down their concentration gradient and does not require energy (ATP).