Biochemistry: Carbohydrates, Lipids, and Membrane Structure

D or L Glucose

Mixed

Vmax- decrease

Km- increase or decrease

If a carbon is bound in the glycolic bond it is

Non reducing

Pyruvate to lactose - cofactors

NADH + H+

Pyruvate to lactose- enzymes

Lactatedehydrogenase

Pyruvate to ethanol - cofactors

TTP /Mg2+ and NADH H+

Pyruvate to ethanol -enzyme

Pyruvate decarboxylate and alcohol dehydrogenase

If Vmax has no change

Competitive

Uncompetitive

Vmax- decrease

Km-decrease

Competitive

Vmax - no change

Km- increase

Anomeric carbons

1 and 6

Ch2oh and oh are the same direction

Alpha

Ch2oh is up

D

Ch2oh is down

L

Ch2oh and OH different directions

Beta

Epimers

differ at one of several asymmetric carbon atoms

Modified Sugars

- Aldonic acid

-Uronic Acid

Reducing Sugars

sugars with anomeric carbons that have not formed glycosides

glycosidic bond

Non-reducing sugars

sucrose

Reducing sugars

- Glucose

-Fructose

-Lactose

-maltose

if the molecule contains one or more C-C double bonds between carbons it is

unsaturated

The more the double bonds, the _____ the melting point

lower

low mp=

liquid, flexible, oil

high mp =

stiff, solid fat

Majority of fatty acids are found as

triacylglycerols

structure of triacylglycerols

1) 3 fatty acids

2) bound by ester link

3) to glycerol

nonpolar and hydrophobic

structure of glycerophospholipids

-Glycerol back bond

- fatty acid

- fatty acid

- Po4 - alcohol

What is the primary constitute of cell membrane

phospholipids

Structure of sphingolipids

A sphingosine backbone attached to a single fatty acid via an amide linkage, with a variable 3rd position

Most common type of steroid, maintains membrane fluidity

cholesterol

When warm cholesterol

restricts moment by pulling phospholipids close together

When cold cholesterol

increases flexibility by pushing them away

The longer the acyl chain, the more ______ the packing in the membrane and the ____ the melting point

Rigid, higher

The more saturated the acyl chain, the more _____ the packing in the membrane and the ______ the melting point

Rigid, higher

Under physiological conditions membranes are more

fluid like than gel like

Flippase

requires ATP to transport lipids from one leaflet to another (more PE to PS )

Floppase

moves phospholipids from cytosolic to outer leaflet

Scramblase

moves lipids in either direction, toward equilibrium

High energy compounds

- ATP

- CoA

- Reduced Cofacotors (NADH, NADPH, QH2)

How many phosphoester bonds are in ATP

1

phosphoester bond

Phosphoanhydride Bonds

Hydrolysis of ATP is highly favorable under standard conditions because

1. Better charge separation in products

2. Better solvation of products

3. resonance stabilization