Ch .2 - Cell Structure

Question 1

What are the elements of living cells?

Answer 1

1. plasma membrane
2. cytoplasm
3. chromosomes (DNA)
4. ribosomes
5. Cytoskeleton - this is debated

Question 2

what is the plasma membrane

Answer 2

surrounds a cell and is made up of a bilayer of phospholipid molecules and then contains protein molecules within it

Question 3

3 things phospholipids are made of?

Answer 3

1. choline
   2.phosphate
2. glycerol

Question 4

what are the two ends the phosopholipids bilayer has?

Answer 4

1. hydrophobic (non -polar)
   -will dissolve
   - aka the tail (phosolipid molecules)
2. Hydrophilic (polar)
   -head (“)

these tails together and head on the outside

Question 5

what are membrane proteins?

Answer 5

they are considered a transporter and can travel thru the inner or outer leaflet (or both)

they also only bind the membrane surfaced

this is how unique cells are created and helps w/ communication

Question 6

what does semi-permeable membrane do?

Answer 6

allows certian things (like water) to flow in and out of a cell - others may need the help of proteins to travel thru

Question 7

Are DNA molecules are found in all cells?

Answer 7

Yes, all cells have this in central regions and they contain genes (contains chromosomes covered by a membrane)

Question 8

what does cytoplasm fill?

Answer 8

it fills the cell and is enclosed by the cell membrane but doesn’t;t fill centre of the nucleus (in eukayrotic)

Question 9

what is cytosol?

Answer 9

it’s an aqueous portion of cytoplasm w/in the cell that contains water and dissolved different ions and organic material

Question 10

what does the cytoskeleton help with regarding internal structure?

Answer 10

it helps give the cell shape, aids in cell division and chromosome split

Question 11

What shapes do prokaryotic cells come in?

Answer 11

1. spherical
2. rodlike
3. spiral

Question 12

what are the two domains of prokaryotic cells

Answer 12

1. bacteria
2. archaea

Question 13

what is the cell wall like?

Answer 13

ridged cell wall and covered with polysaccharids ( glycocalyx , sugar coat)

Question 14

what is a cell capsule made of?

Answer 14

loosely connected glycocalyx to the cell that creates a slime layer

Question 15

what do cytoskeletons help with in prokaryotic cells?

Answer 15

• helps with cell division
• helps the movement of flagella in some cells if they are present in liquids
• helps with pili or pilus in cells that have it - this helps with adhesion, colonization and mating (spikes along surface)

Question 16

domain of eukaryotic cells? and then kingdoms?

Answer 16

Eukarya = protist, animal, plant and fungi

Question 17

Where are ribosomes found?

Answer 17

freely in the cell or studded in the rough ER

Question 18

Where does respiration occur within a cell?

Answer 18

the mitochondria

Question 19

What do animal cells have that plant cells don’t

Answer 19

-lysosomes
-centrioles
-flagella (some plant sperm and moss does)

Question 20

what are some organelles plants have that cells do not have?

Answer 20

chloroplast
central vacuole (and tonoplast=membrane)
cell wall (plasmodesmata)

Question 21

what is a nuclear pore?

Answer 21

protein lined channel in the lipid bilayer aka the envelope and allows molecules in and out like RNA

Question 22

what is the nucleolus’s job?

Answer 22

to assemble ribosomes (production)

Question 23

what is chromatin’s job?

Answer 23

has DNA and proteins to help fold and condense chromosomes in the nucleus

Question 24

what is nuclear laminate

Answer 24

helps aid in structure and pushes things out of the pore - made of dense filaments and proteins

Question 25

what is the ribosomes main job?

Answer 25

- creates all the protein in the cell and does this by performing protein synthesis -they also decode the mRNA and transcribe it to tRNA

Question 26

what are ribosomes made of?

Answer 26

ribosomal RNA's and other proteins - they are broken down into a small and big subunit

Question 27

what are all the parts of the end-membrane system?

Answer 27

nuclear envelope, lysosomes, vesicles, the ER, and Golgi apparatus, as well as the plasma membrane

Question 28

what is the smooth ER?

Answer 28

-it has no ribosomes and performs lipid and steroid synthesis (sometimes regulates carb metabolism) - stores calcium in specialized form on muscle cells -detox toxins and drugs (like alcohol. too)

Question 29

what is the rough ER?

Answer 29

- studded w ribosomes -modifies and folded ribosomes - creates membrane proteins and phospholipids molecules quick and well

Question 30

what does the Golgi apparatus do?

Answer 30

-it is the shipping and receiving of vesicles -contains and flat sac called cisternae

Question 31

what are the two parts of the GA and what do they do?

Answer 31

1. Cis face - receives vesicles and initiates the modicifaction process from the ER and then the middle of the GA processes them 2. Trans face - final step in modifying and packaging the proteins/lipids into vesicles to be shipped

Question 32

what are the vesicles job?

Answer 32

-tool to organize cellar substances like proteins and lipids - they can either process secretion from a cell (exocytosis) -or they can process uptakes (endocytosis) -or move molecules around the cell (intercellular trafficking)

Question 33

what are lysosomes ?

Answer 33

-they are the cells digestive compartments and contains hydrolytic enzymes - their roll is to hydrolyze proteins, fats, polysaccharides and nucleic acid -performs phagocytosis and autophagy

Question 34

what is autophagy ?

Answer 34

the cell degrades and recycles it's own parts

Question 35

what is phagocytosis?

Answer 35

uses the plasma membrane to eat large particles and form membrane bound compartments called phagosomes also forms food vacuoles

Question 36

what are central vacuoles?

Answer 36

membrane bound organelles that store minerals, nutrients, pigments, etc and help to grow turgor pressure to support a cell grow (plant)

Question 37

contractile vacuoles

Answer 37

pumps in and out water and can help a cell move in na liquid environment

Question 38

what does the mitochondria do?

Answer 38

produces ATP by sugars are broken down into molecules and into energy (cellular respiration happens here) they are special and contains their own genome and replicates themselves

Question 39

what does chloroplast do?

Answer 39

breaks down sugars through Co2 and stores energy for the plant as well they are special and contains their own genome and replicates themselves

Question 40

what is the mitochondria made of and it's functions?

Answer 40

it's made of a smooth outer layer and a folded Cristae inner layer - between these spaces two places are made 1. inter membrane space 2. matrix the larger area provides room for enzymes to synthesize ATP

Question 41

3 structures found in chloroplast

Answer 41

1.outer/inner membrane 2. thylakoids 3. Stroma (breaks down things)

Question 42

key role of peroxisome

Answer 42

oxidation of lipids and there breakdown only - bounded by a single membrane does this by producing hydrogen peroxide and converting them to water

Question 43

3 parts and 3 roles of the cytoskeleton?

Answer 43

1. microtubules 2. microfilaments 3. intermediate filaments a. support b. mobility 3. regulation

Question 44

distinct features of microtubules

Answer 44

- hollow tubes contain 13 columns of tubublin molecules -aplha and beta protein unit forms and creates a grain of the tubulin -helps cell shape and motility of cilia/flagella -they create the spindle to divide the cell

Question 45

features of microfilaments

Answer 45

-two intertwined actin strands made of single proteins (two strands create this) -helps in shape and muscle contractions!!! -caused of cytoplasmic streaming to aid in the photosynthesis chemical speed -creates pseudopodia which interns caused the cleavage furrow and helps the whole cell body to move

Question 46

features of intermediate filaments

Answer 46

- proteins supercollider into thicker cables - single protein that twists off and colds around -helps shape the wall -anchors nuclei into the cneter and form nuclear laminate

Question 47

what is the acid used in microfilaments

Answer 47

it's a g actin monomer

Question 48

what is myosin

Answer 48

in microfilemtna and helps with muscle movement, cell division and tension and steaming - microfilemtant forms actin sheets and the myosin sits in between the sheets with the legs against the actin sheets - this causes the legs to move a certain when when activated (contractions)

Question 49

what are cell walls made of?

Answer 49

cellulose fibers, proteins and polysaccharides and have numerous layers (primary, middle lamella, secondary)

Question 50

what are ECM

Answer 50

extraceullar matrix in animal cells and are made of different glycoproteins and macromucles to help with support, adhesion, movement and regulation

Question 51

list of intercellular junctions

Answer 51

*they how cells adhere and communicated 1. plasmodesmata (plant cell only) 2. tight junctions 3. gap junctions 4. desmosomes share symplast

Question 52

what are the differences in the animal junctons

Answer 52

1.tight - cells are pressed together with no opening or space (used f the cell is polar and needs polarity) 2. desmosomes - anchors and fastens the cells together 3. gap - creates pore in-between cells to have rapid communication

Question 53

why do animal cells have 3 junctions?

Answer 53

they need stability, communication and barriers - they don't have a cell wall like plant cells