chapter 3 review

Question 1

What is the nucleus?

Answer 1

houses DNA and is the control center

Question 2

what is the cell membrane?

Answer 2

extremely thin and is selectively permeable

made of lipids and proteins (integral and peripheral proteins)

aid in transport

Question 3

what is the integral protein?

Answer 3

penetrate the hydrophobic core of lipid bilayer
(in cell membrane)

Question 4

what is the peripheral protein?

Answer 4

not in lipid bilayer, attached to surface of the cell membrane

Question 5

what does selectively permeable mean?

Answer 5

only allows specific molecules to pass

Question 6

what is the membrane permeable to?

Answer 6

gases, small lipophilic molecules, and water

Question 7

what is the membrane impermeable to?

Answer 7

larger, uncharged polar molecules and ions

Question 8

what is the cytoplasm?

Answer 8

fills the cell

Question 9

what is the cytoskeleton?

Answer 9

a network of protein filaments& microtubules in cytoplasm
(controls cell shape)
(involved in movement)

Question 10

what is diffusion?

Answer 10

molecules or ions in a liquid solution or air, move from high to low concentration

Question 11

what is facilitated diffusion?

Answer 11

substances too large can not pass through the lipid bilayer

(to move down concentration gradient/ they need help of a membrane protein)

Question 12

what is osmosis?

Answer 12

movement of water across a selectively permeable membrane

Question 13

what is hypertonic?

Answer 13

a solution with a higher osmotic pressure than body fluids

Question 14

what is hypotonic?

Answer 14

a solution with lower osmotic pressure

Question 15

what is filtration?

Answer 15

happens because of hydrostatic pressure, how high or low (i.e; hypo, hyper, or iso)

Molecules are forced through membranes by exerting pressure

Question 16

what is active transport?

(Against concentration gradient)

Answer 16

particles moved low to high concentration

Question 17

what is endocytosis?

Answer 17

Process by which cells absorb external material by engulfing in cell membrane

Question 18

what is pinocytosis?

Answer 18

membrane engulfs droplets containing dissolved molecules from surrounding

Question 19

what is phagocytosis?

Answer 19

engulfs particles from surrounding

Question 20

what is receptor mediated mean?

Answer 20

membrane engulfs selected molecules combined w/ receptor proteins

Question 21

What is exocytosis?

Answer 21

vesicle fuses w/ membrane and releases contents outside of cell

Question 22

what is trancytosis?

Answer 22

vescular transport from one side of a cell to the other

Question 23

what is the cell cycle?

Answer 23

series of changes a cell undergoes from the time it is formed until it reproduces

Question 24

what is interphase?

Answer 24

the cell grows and synthesizes new molecules and organelles

Question 25

What is G1?

Answer 25

where cells do most of their growing

Question 26

What is S?

Answer 26

replicates chromosomes and synthesizes DNA molecules

Question 27

What is G2?

Answer 27

organelle and molecules required for cell division are produced

Question 28

What is anaphase?

Answer 28

Chromosomes move toward the poles of the spindle

Question 29

What is mitosis?

Answer 29

divided into 4 phases (prophase, metaphase, anaphase, telephase) a single cell divides in 2 identical daughter cells

Question 30

what is prophase?

Answer 30

separated genetic material

Question 31

what is metaphase?

Answer 31

spindle fibers attach to centromeres of chromosomes

Question 32

what is telophase?

Answer 32

chromosomes move in opposite directions so two new cells can form from one

Question 33

what is cytokinesis?

Answer 33

splitting of cells

Question 34

what is apoptosis?

Answer 34

cell death

Question 35

what is differentiation?

Answer 35

dividing of cells change their function

Question 36

what are stem cells?

Answer 36

cells that can divide and renew themselves over a long time