Biochemistry Unit 4

In the stomach, oligopeptides are formed from

proteins, HCl, and pepsin

oligopeptides trigger the small intestine to release (1) which causes the pancreas to release (2) and the (3) to constrict

1) CCK

2) digestive enzymes

3) gall bladder

initial digestion products trigger the small intestine to release (1) which causes the pancreas to release (2)

1) secretin

2) bicarbonate, NaHCO3

zymogen

inactive precursor of an enzyme

in the small intestine, enteropeptidase triggers (1) to convert to (2)

1) Trypsinogen

2) Trypsin

this enzyme triggers all other zymogens to turn into their enzyme counterpart

trypsin

how we absorb proteins

proteins are broken into amino acids and oligopeptides by proteolytic enzymes. Oligopeptides are further broken down by peptidases. Amino acids and oligopeptides are transported into the intestinal cell through a symporter and then amino acids are transported out of the cell into the blood stream through an antiporter opposite of Na+

how we absorb carbs

glucose or galactose are transported along side Na+ through a SGLT symporter into the intestinal cell. Fructose is transported into the intestinal cell through a glut5 transporter. all monosaccharides are transported out of the intestinal cell and into the blood stream though a glut2 transporter.

Glycocholate

bile salt released from gall bladder to stabilize nonpolar lipids and bring them to aqueous phase where enzyme are located

Lipase

with the addition of water, this enzyme removes acyl groups from glycerols. Breaks down triacylglycerols into fatty acids and monoacylglycerols

how lipids are absorbed

lipases + water break down triacylglycerols into fatty acids and monoacylglycerols which are then transported into the intestinal cell through the FABP transporter. Phospholipids, cholesterol, proteins, and triacylglycerols are packaged in chylomicrons. The chylomicrons are sent to the lymph system and are later repackaged into lipoproteins. 

Catabolism

converts energy from fuel molecules into biologically useful forms such as ATP, breaking down

Anabolism

Uses biological energy such as ATP to convert simple precursors into complex molecules, building up

Amphibolic

metabolism is either catabolic or anabolic

Delta G^o’

=-RTlnKeq

Delta G

=Delta G^o’ + RTlnQ

Keq=

[prod eq] / [reactants eq]

R=

8.314E-3 kJ/mol K

standard state for H+

1E-7 M

ATP hydrolysis is

exergonic, spontaneous, delta G^o’ <0

hydrolysis of what 2 bonds in ATP releases free energy

phosphoanhydride bonds

which molecules can phosphorylate ADP to ATP

1,3-BPG, phosphoenolpyruvate (PEP), creatine phosphate

primary role of catabolism

to provide the free energy to generate ATP

which compound will release the most energy when fully oxidized

methane

electron carriers for catabolism

NAD+ and FAD

electron carriers for anabolism

NADP+

activated carriers for carbon fragments

Coenzyme A

NAD+

coenzyme, reactive site is sp2 carbon to the left of amide group, acts as an oxidizing agent, causes the formation of a C=O

FAD

reduced form is FADH2, oxidized alkyl groups to alkenes

ADP plus linear sugar and 3 ring structure including nitrogen reactive sites

CoA-SH

SH is the reactive group on coenzyme A

many coenzymes come from

vitamins

you can regulate metabolism by

amount of enzymes, catalytic control, accessibility of substrate

compartmentalization

substrates are restricted from certain areas of cell

Energy charge

form of catalytic control

[ATP] / [ATP+ADP+AMP]

a low energy charge will activate

catabolic metabolism

Where are the reactive sites for FAD

the Nitrogens in the three rings

What causes the negative free energy of ATP hydrolysis

electrostatic repulsion, resonance stabilization, solvent stabilization