Biochem Weightloss Fa Synthesis 1

Front 1

FA metabolism makes Fatty acids for what molecules (list structure)

Back 1

Triacylglycerols (3FA + glycerol backbone)(main E)

Phospholipids ( 2FA + phos'd glycerol)

Cholesterol ester (1FA + steroid ring)

Front 2

Where does FA come from? / is degraded back down to?

Back 2

Acetyl CoA

Front 3

For structure see page 62

Back 3

lkh

Front 4

how long are:
SCFA
MCFA
LCFA
VLCFA

Back 4

s - 2-6 C
m - 6-12
l - 14-20
verylong - 22 and up

Front 5

is a cis or trans dbl bond a kink?

Back 5

cis

Front 6

how far apart must dbl bonds be?

Back 6

at least 3 C's apart

Front 7

which carbon in linoleic acid is C1, carboxy end or methyl end

Back 7

the carboxy carbon

Front 8

palmitic acid
palmitoleic acid

Back 8

16:0

16: 1 delta9

Front 9

stearic acid
oleic acid
linoleic acid
Alpha-linolenic acid

Back 9

stearic: 18:0

oleic: 18:1 delta9

Linoleic: 18:2 delta 9,12

alpha-linoleic: 18:3 delta 9,12,15

Front 10

arachidonic acid

Back 10

20:4 delta 5,8,11,14

Front 11

which ones are in the omega-6 family?

Back 11

linoleic and arachidonic acid

Front 12

which are omega-3?
omega-7?

Back 12

omega-3: alpha-linolenic

omega-7: palmitoleic

Front 13

where does FA synthesis occur

Back 13

cytosol (liver adipose CNS and mammary)

Front 14

overall reaction of FA synthesis

Back 14

8 acetyl CoA
7 ATP
14 NAPH

makes

palmitate 16:0

CoAsh, NADP and water

Front 15

FA synthesis
exergonic vs endergonic
reductive vs oxidative

Back 15

endergonic and reductive

Front 16

Acetyl CoA
structure

Back 16

acetyl group - long flexible phosphopantetheine group - Ribose - adenine

Front 17

panothenic acid, how synthesized in humans

Back 17

not, its an essential nutrient

Front 18

Acetyl CoA carboxylase

what it does
coenzymes?

Back 18

AcetylCoA + CO2 + ATP --> malonyl CoA + ADP + Pi

BIOTIN as a co-enz PROSTHETIC GROUP (cov bound) swinging arm binds CO2 like in pyruvate carboxylase of gluconeogenesis

Front 19

Acetyl CoA carboxylase

importance of the step it catalyzes

allosteric effectors (+and-)

Back 19

makes malonyl CoA in a committed rate limiting irrev step

Allosteric effectors:
+ citrate
- palmitic acid (end product)

Front 20

Acetyl CoA carboxylase

covalent regulation

what causes a positive allosteric effect or a negative allosteric effect

Back 20

inactive when phosphorylated

deP'd when insulin is high (insulin/glucagon ratio is high)
P'd when glucagon is high by AMPK (in assoc with PKA)

Front 21

FAS

Back 21

Fatty acid synthase

catalyzes malonyl CoA and Acetyl CoA to palmitate

7 catalytc activities and an ACP carrier protein domain

Front 22

ACP domain

Back 22

has a posphopantetheine group like in acetyl CoA, uses this swinging arm to link intermediates

Front 23

Describe/ draw out FAS activity

Back 23

Tranferase: takes malonyl CoA and Acetyl CoA and makes malonyl-s-ACP and acetyl s-ACP

combine the two using condensing enzyme (CO2 leaves)

Reduce - beta-ketoacyl reductase (uses NADPH)

Dehydrate (dbl bond between alpha and beta C): beta-Hydroxylacyl dehydratase

Reduce - transenoyl reductase (uses NADPH)

repeatedly combine with malonyl-s-ACP till you get palmitoyl-s-ACP (16:0)

cleave off s-ACP using thioesterase

Front 24

if you use methylmalonyl CoA instead of malonyl CoA what happens

Back 24

you make branched chain FA

Front 25

explain transport of Acetyl CoA out of mito and into cytosol where FA synthesis occurs

Back 25

Mito:
Acetyl CoA + OAA --> citrate
via citrate synthase

citrate is shuttled out

Cytosol:
citrate -->Acetyl CoA and OAA
via Citrate lyase

OAA --> malate via malate DeH

malate goes into mito and this drives the malate citrate transporter, once in mito malate is converted back to OAA (which can then combine with acetyl CoA to make citrate)

Front 26

Refresher how does pyruvate get into the mito?

Back 26

proton pyruvate symporter, uses inter membrane proton gradient

Front 27

where else can you get a source of NADPH (remember you use two per addition of malonyl) besides pentose pathway?

Back 27

malate + nadp --> pyruvate + NADPH

via malic enz

Front 28

refresher
oxidative portion of pentose pathway

Back 28

G6P -(DeH)-> lactone -(lactonase)-> glucontate -(DeH)->

ribose-5-p + CO2 + 2NADPH

Front 29

How does elongation of DIETARY FA differ from de novo?

Back 29

more than one enz
ER bound!
CoA (not ACP)
Substrates are over 10C long

Front 30

How many NADPH does de NOVO syn take to make palmitoyl?

Back 30

14 NADPH

Front 31

in dietary elongation how many NADPH per C added?

Back 31

1 nadph per C (like in de novoe)

Front 32

Where are the C from malonyl CoA added into dietary FA?

Back 32

R-CH2CH2-C(=O)SCoA

at carboxy carbon

Front 33

Question on counting the C's in FAsynthase, follow the C's from malonyl and acetyl, where is alpha beta, where does dbl bond insert

Back 33

???

Front 34

Desaturation of dietary FA

Back 34

insertion of dbl bond, uses :

desaturase
cytochrome b
NADH cytochrom b reductase

ER!

Front 35

Where can humans place dbl bonds

Back 35

at 9, 6, 5, and 4 (the four types of desaturases)

Front 36

where is the limit of desaturation in humans

Back 36

cannot insert beyond C10

Front 37

What family of FA's can humans not synthesis

Back 37

omega-6 and omega-3

Front 38

how do you make arachidonic acid from linoleic? (omega-6)

Back 38

linoleic 18: delta 9,12

desat at 6 (three C's away)

elongate to 2 C's (pushes dbl bonds further away from C1)

Desaturate at 5

get 20:4 5,8,11,14