BSCI330 major organelles

Question 1

what are mitochondria responsible for

Answer 1

oxidative metabolism of carbohydrates, lipids, and amino acids

Question 2

what type of organelles are ribosomes

Answer 2

protein synthesizing organelles

Question 3

what is the ER responsible for

Answer 3

modification and maturation of membrane secreted proteins and lipid synthesis

Question 4

what is the golgi involved in

Answer 4

the modification of proteins and some carbohydrate synthesis

Question 5

what type of structure does the mitochondria have

Answer 5

double-membrane structure

Question 6

what does the outer membrane of the mitochondria contain

Answer 6

channel proteins called porins (allows material to get from cytoplasm into mitochondria and vice versa)

Question 7

what does the inner membrane of the mitochondria contain

Answer 7

rich in cardiolipin; folded into cristae (site of electron transport chain) - inside is bigger than outside - allows bigger surface for membrane

Question 8

what does the intermembrane space of the mitochondria contain

Answer 8

contains cytochrome c (can move between electron acceptor complexes) and other proteins that regulate programmed cell death

Question 9

what does the matrix of the mitochondria contain

Answer 9

site of oxidative metabolism; contains mtDNA (mitochondrial DNA), ribosomes, and other components for expression of mitochondrial genome (RNA polymerase, etc)

Question 10

what shape is the mitochondrial genome

Answer 10

circular - inherited exclusively from mother

Question 11

where are ribosomes found

Answer 11

cytoplasm and within mitochondria and chloroplasts (not enclosed by membrane)

Question 12

what are ribosomes made of

Answer 12

large complexes of protein plus RNA

large and small subunits, which only assemble during protein synthesis

Question 13

what is the ER

Answer 13

complex membranous organelle extending throughout cytoplasm

constitutes about 50% of membrane in eukaryotic cell

Question 14

what happens since the ER is continuous with nuclear membranes

Answer 14

the ER lumen merges with nuclear intermemembane space

Question 15

what is the difference between rough and smooth ER

Answer 15

rough has ribosomes attached to it, smooth doesn’t have ribosomes

Question 16

what is an important thing stored in the ER

Answer 16

Calcium ions, which are important for cellular signaling

Question 17

what is the smooth ER the site of

Answer 17

lipid synthesis and detoxification of lipid-soluble compounds

Question 18

what is the rough ER the site of

Answer 18

transmembrane and secreted protein synthesis

Question 19

what does scramblase do **ON FINAL

Answer 19

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

Question 20

what does flippase do ****ON FINAL

Answer 20

gets appropriate asymmetry in plasma membrane

Question 21

how are ER-synthesized proteins modified

Answer 21

by adding a common oligosaccharide

Question 22

what does N-linked glycosylation help with

Answer 22

protein folding in ER

non-folded can’t leave the ER

Question 23

what is the golgi

Answer 23

central sorting station for proteins and membranes along secretory pathway

synthesis site for most carbohydrates

Question 24

what is the structure of the golgi

Answer 24

made of pancake-like cisternae arranged in a stack

Question 25

what is the difference between cis and trans faces of golgi

Answer 25

cis face of stack is closest to ER
- receives vesicles from ER and proteins will pass through golgi

trans face is furthest from ER
- the exit from Golgi

Question 26

what does golgi do to N-linked glycosylations

Answer 26

modifies them (can remove sugar molecules or add more - can have complex oligosaccharides and high mannose oligosaccharides)

Question 27

what is O-linked glycosylation

Answer 27

sugars are added one at a time

Question 28

what is N-linked glycosylation

Answer 28

preassembled carbohydrates (in ER, transferred to golgi)