Cell Biology

Question 0

hypertonic solution

Answer 0

• concentration of H2O is greater in cytoplasm than in the solution
• concentration gradient exists (H2O is in [HIGH] in cytoplasm than in solution)
• net movement of H2O molecules from cytoplasm into solution
• cell shrinks and dies

Question 1

chromatin: structure & function

Answer 1

function

• contains DNA which has the instructions to control cell activities
• scattered through nucleus in a non dividing cell

structure

• coiled DNA: turned off and cannot make mRNA
• uncoiled DNA: turned on and can make mRNA

Question 2

cilia

Answer 2

• act in unison to move substances across cell surface in one direction
• extensions of the cell membrane to the exterior
• 9+2 arrangement of microtubules

Question 3

microvilli

Answer 3

• increase the membrane surface area for absorption purposes

- projections of the cell membrane

Question 4

nuclear membrane

Answer 4

• semipermeable; selects what enters and exits the nucleus

- encloses nuclear content; a double membrane with pores

Question 5

rough er

Answer 5

• where proteins produced by its ribosomes enters subway system; transports proteins to smooth er
• throughout cytoplasm

Question 6

smooth er

Answer 6

• area of subway system where compounds likes proteins leave the er in a membrane bound sac
• produces phospholipids
• in cytoplasm near golgi

Question 7

cytoskeleton

Answer 7

• support and suspend structures of the cell

- microtubules and microfillaments

Question 8

active transport

Answer 8

• active transport mechanism
• needs carrier protein
• ATP required
• [LOW]->[HIGH]
• sodium potassium pump

Question 9

phagocytosis

Answer 9

• cell engulfs a substance within a membrane bound sac

- ATP required

Question 10

osmosis

Answer 10

• no ATP required

- H2O goes through [HIGH WATER]->[LOW WATER] through semipermeable membrane

Question 11

exocytosis

Answer 11

• ATP required
• membrane bound vesicle attaches to to the plasma membrane and releases its contents to the exterior
• vesicle membrane becomes part of plasma membrane

Question 12

ATP

Answer 12

-produced when covalent bonds of glucose are broken and the energy released is stored in the high energy bond of ATP

Question 13

equilibrium

Answer 13

-no net diffusion

Question 14

cellular respiration

Answer 14

C6H12O6 + 6O2 -> 6CO2 + 6H2O + 36 ATP

Question 15

photosynthesis

Answer 15

6CO2 + 6H2O -> C6H12O6 + 6O2

Question 16

ATP - mitochondria

Answer 16

• controls release of energy from foods

- forms atp through cellular respiration

Question 17

cell membrane

Answer 17

• external boundary of the cell

- confines cell contents; regulates what goes into and out of cell (semipermeable)

Question 18

hypotonic solution

Answer 18

• concentration of salt/solute and H2O are not equal on either side of cell membrane
• H2O is in [HIGH] outside the cell and [LOW] within cell
• net movement of H2O molecules into cell
• cell swells and explodes

Question 19

nucleolus

Answer 19

• dark spherical area within nucleus

- assembly area for ribosomes

Question 20

receptor proteins

Answer 20

• specific site that allows a specific molecule to bind to it
• chemical messenger of hormone must fit receptor site in order to affect the metabolism of the target cell

Question 21

sodium potassium pump

Answer 21

• specific carrier protein that is present in neuron cell membranes
• transports 3 sodium ions from the neurons cytoplasm into surrounding interstitial fluid
• 2 potassium ions from the interstitial fluid into the neurons cytoplasm

Question 22

nucleus

Answer 22

• usually in centre shaped in an oval or circle
• stores genetic info in the form of genes in DNA
• directs cellular activities

Question 23

fluid mosaic

Answer 23

-based on the changing location (fluid) and pattern of proteins (mosaic) in the phospholipid bilayer

Question 24

facilitated diffusion

Answer 24

- requires transport protein to move substances faster than normal diffusion - O2 transport to blood - [HIGH]->[LOW] - no ATP required

Question 25

lysosomes

Answer 25

- scattered throughout cytoplasm - contains digestive enzymes that break down ingested materials within cell - also break down worn out organelles

Question 26

Golgi apparatus

Answer 26

- in cytoplasm near nucleus - forms membrane bound sac - lysosomes - also form membrane bound sacs called secretory vesicles

Question 27

centrioles

Answer 27

- two rod shaped bodies near nucleus | - may be involved with production of spindle fibres that pull apart sister chromatids of each chromosome

Question 28

ribosomes

Answer 28

- attaches to rough er or scattered into the cytoplasm | - synthesize proteins (enzymes, hormones, structural proteins)

Question 29

vesicles or vacuoles

Answer 29

- throughout cytoplasm | - transports or stores nutrients, cell waste products, hormones, proteins like hormones and enzymes, etc

Question 30

peroxisomes

Answer 30

- throughout cytoplasm; a membrane bound sac | - detoxifies alcohol and free radicals that accumulate from normal metabolism in liver

Question 31

cell wall

Answer 31

- surrounds cell membrane in plant cells (cellulose) | - permeable: allows particles to move freely in either direction; support

Question 32

chloroplasts

Answer 32

- cytoplasm of plant cells and green algae - photosynthesis: using solar energy - H2O and CO2 react to form organic compounds and O2

Question 33

inter-relationship between Golgi apparatus, etc and secretion

Answer 33

- gene in DNA (nucleus) makes mRNA - mRNA goes through nuclear pore to cytoplasm - rough er (ribosomes of rough er) - polypeptide; must take specific shape to become a functional protein - enters rough er - transported to smooth er - transport vesicle - golgi apparatus - lysosomes (hydrolytic enzymes) and transport/secretory vesicle-> contents of vesicle leaves by exocytosis