Ch. 3

Question 1

What are the two types of cells and their characteristics?

Answer 1

1. Prokaryotes: lack a true nucleus and membrane bound organelles. Small (1 um). Bacteria and Archebacteria.
2. Eukaryotes: have a true nucleus and membrane bound organelles (10um-100um) so they are bigger, include animals, plants, fungi, and protista

Question 2

Why do we study prokaryotes in anatomy and physiology?

Answer 2

We study them because of bacteria on the body

Question 3

What can cross the cell membrane?

Answer 3

non-polar molecules
small, uncharged polar molecules
Charged ions (may have to use a transport protein)

Question 4

What are the functions of the cell (plasma) membrane? How?

Answer 4

1. Controls and regulates what goes in and out of the cell
   - Occurs because of its phospholipid bilayer
2. contains receptors which allows cell to respond to its environment
3. Provides structure

Question 5

cytoplasm

Answer 5

intracellular fluid

Question 6

organelles

Answer 6

“little organs,” specialized structure inside the cell that performs specific jobs

Question 7

nucleus

Answer 7

• Is the “command and control center” of the cell
• Is surrounded by a double layered membrane called the nuclear envelop
• contains most of the cell’s DNA

Question 8

What is DNA?

Answer 8

The “master blueprint” for the cell since it contains information on how to make proteins

Question 9

Nucleolus

Answer 9

Area inside the nucleus where the subunits of the ribosomes are pre-made before being shipped out of the nucleus to the cytoplasm

Question 10

ribosomes

Answer 10

organelle where protein synthesis occurs (builds proteins)

Are NOT surrounded by a membrane

Can be bound to the ER or free (floating) in the cytoplasm

Question 11

Endoplasmic Reticulum (ER)

Answer 11

A network of tubes that may be 2 types:

1. Rough ER: ribosomes attached make proteins and ships around cell makes new ER
2. Smooth ER: No ribosoms; synthesizes lipids, phospholipids, and steroids. Helps carb metabolism; detoxifies certain drugs; stores some calcium ions

Question 12

vesicles

Answer 12

found in animal cells where they store and ship small compounds around the cell (“small baggies”)

Question 13

golgi apparatus

Answer 13

modifies, stores, and sorts the products shipped to it from the ER (shipping warehouse)

Question 14

lysosomes

Answer 14

contain enzymes that can digest all types of macromolecules

1. phagocytosis: enzymes help the cell break down ingested macromolecules for energy
2. autophagy: can digest other organelles or cytoplasm for recycling
3. programmed cell destruction: releases enzymes in a burst that dissolves the entire cell

Question 15

What enzymes can lysosomes contain?

Answer 15

• proteases: proteins
• lipases : lipids
• carbohydrases: breakdown carbohydrates
• nucleases: nucleic acids

Question 16

mitochondria

Answer 16

site of cellular respiration. creates ATP
- found in almost all eukaryotic but not prokaryotic
- larger number in highly active cells
contain their own ribosomes and own DNA
-reproduce on own ass needed

Question 17

cytoskeleton

Answer 17

a network of fibers throughout the cytoplasm that builds a framework for support and movement

Question 18

Passive transport

Answer 18

the diffusion of a substance across a membrane. No energy required

Question 19

diffusion

Answer 19

the movement of a molecule from an area of high concentration to an area of lower concentration

continues until all molecules of the solute are equally dispersed throughout the solution

rate depends on 1) size of the molecule and 2) temperature of the solution

Question 20

facilitated diffusion

Answer 20

diffusion of a solute across a membrane using a transport protein
- no energy required

Question 21

osmosis

Answer 21

diffusion of water across a selectively permeable membrane

Question 22

osmotic concentration

Answer 22

total concentration of solute in a solution

Question 23

osmotic pressure

Answer 23

a measure of how easily a solution takes up water

Question 24

hypotonic solution

Answer 24

a solution with a lower solute concentration than the solution it is being compared against

Question 25

isotonic solution

Answer 25

a solution with a solute concentration that is equal to that of a solution it is being compared against

Question 26

hypertonic solution

Answer 26

a solution with a greater solute concentration than the solution it is being compared against

Question 27

What happens when animal cells are exposed to the following?

1. hypertonic solution
2. hypotonic solution
3. isotonic solution

Answer 27

1. cell loses water to the outside environment and shrivels (crenulates)
2. cell gains water and may rupture (lyse)
3. cell gains and loses equal amounts of water so stays stable

Question 28

What happens when plan cells are exposed to the following?

1. hypertonic solution
2. hypotonic solution
3. isotonic solution

Answer 28

1. Water moves out of the cell. As it shrivels, plasma membrane moves from the cell wall resulting in cell death
2. water moves in until pressure is equalized. causes cell to become turgid
3. no net movement in or out. The cell becomes limp (wilts)

Question 29

active transport

Answer 29

A transport protein uses energy to pump a molecule across membrane into its concentration gradient

ATP is most common energy transfer molecule

Costs energy

Question 30

Co-transport

Answer 30

a form of active transport where a transport protein uses energy (or ATP) to actively transport one solute and indirect moves another solute against its concentration gradient

Ex. Na-K+ pump

Question 31

What methods do large molecules use to cross membranes?

Answer 31

1. Exocytosis

2. Endocytosis

Question 32

3 types of endocytosis?

Answer 32

1. phagocytosis
2. pinocytosis
3. receptor meditated cytosis