glucose

Prokaryotic Gene Regulation

lactose or glucose as a sole carbon source, while certain mutant

strains are only able to use glucose. We would have called the

E. coli are Lac and can grow on glucose

by itself, not metabolizable by E. coli) into glucose and galactose.

specified, a Lac strain can grow on glucose as

E. coli

mineral ions, and an energy source such as glucose. Unlike some

2 Sugars

2 Sugars

large amounts of energy. For example, the complete metabolism of glucose:

Amylose and cellulose, composed of long chains of glucose molecules, are examples of polysaccharides. The only structural difference between them is the linkage between the glucose molecules, yet the compounds have very different properties. Cellulose is a tough material found in plant cell walls, whereas amylose (a form of starch) is water soluble and used by plants as a carbon storage compound.

MIT Biology Hypertextbook: Enzyme Mechanisms

lactose --> glucose + galactose

Membrane Proteins Introduction

if the E. coli also detects a high concentration of glucose in the

the glucose. It also needs to pump in nutrients and release toxic products

Membrane Transport Mechanisms

The Na+-glucose secondary transport mechanism

the glucose-Na+ symport protein uses that Na+ gradient to transport glucose

take in glucose and Na+ from the intestines and transport them through to the

blood stream using the concerted actions of Na+-glucose symports, glucose

permeases (a glucose facilitated diffusion protein), and Na+-K+ pumps. Note

Culturing cells in vitro

addition, the cell requires glucose for energy, oxygen (coming from the

Chemical Energetics

glucose +Pi --/--> glucose-6-phosphate

glucose + Pi --> glucose-6-P + H20 requires energy.

the overall reaction: glucose + ATP --> glucose-6-P + ADP, which is

donor of phosphate to glucose.

phosphate groups to glucose and thereby increased the reactivity of the

glucose so that it could be used for other reactions. In the second

conversion of glucose to lactic acid, which serves to produce ATP for

glucose + ATP --> glucose-6-phosphate + ADP

potential. For example, if glucose-6-P were to hydrolyze in water it

Solving Chemical Equilibrium Problems

1.) The catabolism (break-down) of glucose is an important source of

Glucose --> Glucose-6-Phosphate

Theoretically, the cell could phosphorylate glucose directly with

, meaning that energy must be expended to

c) In a typical cell, glucose and phosphate are maintained at

concentration of Glucose-6-Phosphate if the cells used the reaction as

d) Does this direct phosphorylation of glucose represent a

reasonable route for the catabolism of glucose? Explain briefly.

e) The cell actually accomplishes the phosphorylation of glucose by

src="glucose6.GIF"> for the net reaction.

g) The concentration of Glucose-6-Phosphate typically found in cells is

what concentration of glucose would be necessary to yield the observed

Glucose-6-Phosphate concentration if the reactions are coupled?

h) In addition to being phosphorylated by hexokinase, glucose may also

much higher KM for glucose than does hexokinase. Given that the KM's

for glucose are 10.0 mM (glucokinase) and 0.10 mM (hexokinase) and given

what would be the molar ratio of glucose-hexokinase complexes to

glucose-glucokinase complexes in a cell when the concentration of

glucose is 4.8 mM?

G = Glucose

G-GK = Glucose-glucokinase complex

G-HK = Glucose-hexokinase complex

Glucose-hexokinase complexes outnumber glucose-glucokinase complexes by

3 : 1 because hexokinase binds more tightly to glucose than does

3 Enzyme Kinetics

lactose -----------------------> glucose + galactose

For this reaction, measuring the formation of glucose would constitute

in the 'normal' reaction, y-galactose = lactose = glucose-galactose (y=glucose)

7.01Recombinant DNA Practice Problem

iv) Why can't you use lactose alone instead of glucose?

G Protein Receptors

to skeletal muscles, and increases blood glucose by causing liver and

muscle cells to break down glycogen and release resulting glucose into

glucose-l-phosphate molecules; and

thereby preventing the reconversion of the released glucose to

glycogen. These two changes together ensure the mobilization of glucose

3.2 Basic Kinetics

P product (glucose or galactose)

Membrane Transport Problem Answers

a) What kind of mechanism allows glucose to enter the intestinal

color will help you a lot. Glucose is transported from the gut into

intestinal epithelial cells. The energy to transport glucose up its

sodium ion that was pumped out with the use of ATP pushes the glucose

A mechanism similar to the Na-glucose symport secondary transport system

Cell Biology Chapter

The Glucose-Na+ Transport System

3.5 Solving Enzyme Kinetics Problems

step in growth, which strain will grow faster if the concentration of glucose

3.4 Primary through Quartenary structure

glucose molecule bound to it, but that is nearly impossible to see.