exam 1 major organelles

Question 1

what is the mitochondria responsible for

Answer 1

oxidative metabolism of carbohydrates, lipids, and amino acids

Question 2

what are the protein-synthesizing organelles in cells

Answer 2

ribosomes

Question 3

what is the ER responsible for

Answer 3

modification and maturation of integral membrane and secreted proteins, and for lipid synthesis

Question 4

what is the golgi involved in

Answer 4

sorting center for proteins and membranes

modification of proteins

Question 5

what is evidence for endosymbiotic theory

Answer 5

mitochondria contain ribosomes

mitochondrial inner membrane is rich in lipid, cardiolipin

Question 6

what is the endosymbiotic theory

Answer 6

some organelles used to exist as free-living organisms

Question 7

what does mitochondria generate

Answer 7

most of the cell’s ATP

Question 8

what membrane structure do mitochondria have

Answer 8

double membrane - two membranes, unlike nucleus with folded

Question 9

what is the outer membrane of the mitochondria full of

Answer 9

porins (channel proteins)

Question 10

what is the outer membrane of the mitochondria similar to

Answer 10

plasma membrane

Question 11

what is the inner membrane full of

Answer 11

cardiolipin - rare in eukaryotic, abundant in prokaryotic

Question 12

what is the inner membrane folded into and why

Answer 12

cristae - increases surface area of inner membrane relative to outer membrane

Question 13

what is the inner membrane the site of

Answer 13

electron transport chain - more surface area = more electron transport = more metabolism

Question 14

what does the intermembrane space of mitochondria contain

Answer 14

cytochrome c and several factors that regulate programmed cell death

Question 15

what is the mitochondrial matrix the site of

Answer 15

oxidative metabolism + contains mtDNA, ribosomes, and other components for expression of mitochondrial genome

Question 16

what is oxidative metabolism

Answer 16

oxygen combines with electrons and protons to form water

Question 17

who is the mitochondrial genome inherited from

Answer 17

the mother

Question 18

who is mitochondrial Eve

Answer 18

single woman in Africa many years ago, who is the ancestor of all current living humans

Question 19

where are ribosomes found

Answer 19

in cytoplasm and within mitochondria and chloroplasts

Question 20

are ribosomes enclosed by a membrane

Answer 20

no

Question 21

what are ribosomes made of

Answer 21

large complexes of protein + RNA, which are structural components

Question 22

what are the two subunits of the ribosome

Answer 22

large and small

Question 23

when do the ribosomal subunits assemble

Answer 23

when protein synthesis initiates

Question 24

where does the ER extend throughout

Answer 24

the cytoplasm

Question 25

what does endoplasmic mean

Answer 25

contained within cytoplasm

Question 26

what does reticulum mean

Answer 26

mesh-like network

Question 27

what is the ER continuous with

Answer 27

nuclear membranes

Question 28

what does the ER lumen merge with

Answer 28

nuclear intermembrane space

Question 29

what is the rough ER

Answer 29

associated with many ribosomes

Question 30

what is the smooth ER

Answer 30

lacks attached ribosomes

Question 31

what is the ER storage for

Answer 31

storage for calcium ions (for cell signaling)

Question 32

what is the function of the smooth ER

Answer 32

lipid synthesis and detoxification of lipid-soluble compounds

Question 33

what is the function of the rough ER

Answer 33

synthesis of transmembrane and secreted proteins

Question 34

what is the purpose of scramblase

Answer 34

gets lipids into both ER leaflets - phospholipid molecules flip and there is symmetric growth of both halves of the bilayer

Question 35

what is flippase

Answer 35

gets appropriate asymmetry in plasma membrane by selectively moving some lipids from outer leaflet to inner and vice versa

Question 36

how are rough ER-synthesized proteins modified

Answer 36

by adding a common oligosaccharide

Question 37

why is N-linked glycosylation called that

Answer 37

the attachment site is the -NH2 group of an asparagine

Question 38

what does N-linked glycosylation help with

Answer 38

protein folding in ER - carbohydrates attach to amine group of asparagine

Question 39

what indicated something is not properly folded

Answer 39

hydrophobic residue on outside

Question 40

what does the golgi do along the secretory pathway

Answer 40

central sorting station for proteins and membranes

Question 41

what does the golgi consist of that creates its shape

Answer 41

a series of flattened discs called cisternae arranged in a stack

Question 42

what is the cis face of the golgi

Answer 42

closest to ER and receives vesicles containing ER-synthesized proteins

Question 43

what is the trans face of the golgi

Answer 43

furthest from ER and represents the exit from golgi

Question 44

what is the golgi the synthesis site of

Answer 44

most cellular carbohydrates

Question 45

what happens to N-linked oligosaccharides in ER

Answer 45

in ER on asparagine - trimmed and further processed by addition of other sugars to generate high mannose oligosaccharides

Question 46

what is N-linked glycosylation compared to

Answer 46

buying something off the rack - uses common carbohydrate

Question 47

what is O-linked glycosylation compared to

Answer 47

getting clothes custom made - unique

Question 48

what happens with O-linked glycosylation

Answer 48

proteins get carbohydrates added to the hydroxyl group of serine or threonine in Golgi

Question 49

why does N-linked glycosylation use a pre-formed common carbohydrate that is later modified for each protein

Answer 49

the process simplifies regulation

the common carbohydrate has one function in the ER, and then new functions can be added by modifying the carbohydrate on individual proteins later