Lecture 13

• August 29, 2005

• Lehninger (4th Edition), Chapter

Skip the details on the metabolism of ketone bodies

Metabolic Biochemistry

FATTY ACID SYNTHESIS

LNC Chapter 21

LNC Fig. 21-1

the enzyme has threefunctional regions:

- biotin carrier protein- biotin carboxylase- transcarboxylase

acetyl-CoA + CO2 ==> malonyl-CoA

LNC Fig. 21-4

acyl carrier protein

LNC Fig. 21-2

End of lecture 12

August 26, 2005

LNC Fig. 21-2

LNC Fig. 21-2

LNC Fig. 21-2

This group is transferred tothe other SH group to free the ACP-SH for the nextmalonyl group

LNC Fig. 21-3

LNC Fig. 21-5

LNC Fig. 21-5

LNC Fig. 21-5

LNC Fig. 21-5

LNC Fig. 21-5

LNC Fig. 21-5

LNC Fig. 21-5

LNC Fig. 21-5

LNC Fig. 21-6

beginning of the second round:

LNC Fig. 21-7

LNC Fig. 21-13

The normal product of fatty acid synthase is palmitate (16 carbons)

elongation to stearate and longer chainstakes place in the endoplasmic reticulum (ER)

desaturation to oleate also occurs in the ER

poly-unsaturatedthe shaded fatty acids are essential FAfor humansbut are made only in plants

Desaturation of fatty acids in vertebrates (in the smooth ER):

requires molecular oxygen

LNC Fig. 21-8

Source of NADPH

Malic enzyme is found in liver and other animal tissues

A similar enzyme is found in bundle sheath cells in C4 plants

LNC Fig. 21-9

Source of NADPH

Source of NADPH

photosynthesis

from glucose to fatty acids

glucose pyruvate (in cytosol)

pyruvate acetyl-CoA (in mitochondria)

acetyl-CoA fatty acid (in cytosol)

How does acetyl-CoA come out of mitochondria ?

From glucose to fatty acids

mitochondria cytosol

LNC Fig. 21-11

Biosynthesis of cholesterol

steroidsisoprenoids

LNC pp. 799

LNC Fig. 21-30

LNC Fig. 21-32

CH3 CH3

CH2 C CH CH2 CH2 C CH CH2

n

Polyisoprene

LNC Fig. 21-36

LNC Fig. 21-37a

LNC Fig. 21-38

LNC Fig. 21-40

LNC Fig. 21-41

LNC Fig. 21-42

3-isopentenyl pyrophosphate

LNC Fig. 21-48

STEROID HORMONESVITAMIN D

RUBBER

DOLICHOLS

QUINONE

OTHER VITAMINS

CAROTENOIDS

PLANT HORMONES

C |CH2 = C – CH2 – CH2 – O - P - O - P

Skip several pages in chapter 21 (pp.784 - 798)

read p. 785 about function/mechanism of aspirin, ibuprofen and other painkillers and related drugs

End of lecture 13August 29, 2005