Glucides 1.1:

Question 1

What kind of sugar is glucose

Answer 1

Aldose hexose

Enantiomers:
De-glucose: OH is a droite

L-glucose: OH is a gauche

Question 2

How can you get glucose from manose?

Answer 2

Via an epimerase

This is because manose and glucose are epimeres

Question 3

What can change the structure of glucides from cyclique to lineare?

Answer 3

EXAM QUESTION:
the pH
L’équilibre entre les formes varie en fonction de l’environnement
* À pH neutre, ≈99% cyclique (plus stable)
* À pH basique, ≈99% linéaire

Question 4

Major glucose form in our bodies:

Answer 4

beta-delta- gluco pyranose (for cyclic)

Forme chaise en solution = plus stable

Question 5

alpha vs beta bonds?

Answer 5

alpha bon : oh in the bottom, beta bond: OH on the top

Question 6

3 dissacharides:

Answer 6

• Saccharose:
• D-glucose + D-fructose
• alpha bond
• Lactose:
• D-glucose et de D-galactose
• beta bond
• Maltose:
• D-glucose - D-glucose
  *

Question 7

Amidon, Saccharose and Lactose digestion

Answer 7

Amidon:
it is a polysaccaride to first broken into maltose then into glucose

Saccharose:
disacaride so directly broken itno glucose and fructose

Lactose:
disacchiride broken into glucose and galactose

Question 8

GLUT that Responds to insulin

Answer 8

GLUT 4

insuline incresses its expression, problem in diabetics

Question 9

What is special of GLUT2?

Answer 9

it is the glucosensor in glycolyse vs neoglycogenesis

Question 10

Exam Question

What induces insulin secretion?

Answer 10

Les sucres
- Glucose
- Mannose
* Les acides aminés
- Leucine
- Arginine
* La stimulation du nerf vague
* Peptides entériques

Question 11

Action of insulin

Answer 11

ACTIVATION de la synthèse de glycogène (glycogenèse)
* INHIBITION de la dégradation du glycogène (glycogénolyse)
* ACTIVATION de la dégradation de glucose (glycolyse)
* INHIBITION de la synthèse de glucose (néoglucogenèse)
* ACTIVATION de la synthèse des lipides (lipogenèse)
* INHIBITION de la dégradation des lipides (lipolyse

Question 12

Glucagon role?

Answer 12

It is a hormone that wants to increase glucose levels in the blood

Question 13

What is Glycogenèse?

Answer 13

The action of transforming glucose into glucogene to store it

Question 14

Glucogenesis steps:

Answer 14

st step is important:

Glucose à Glucose-6-phosphate
hexokinase

UTP (UDP) is important for the synthesis of long chains
UDP-glucose + Glycogènen à Glycogènen+1 + UDP

Question 15

What is Glycogénolyse?

Answer 15

Breakdown of glucogen to get glucose

important enzyme: glucose-6-phosphatase ** dans le foie uniquement **, exam q)

Question 16

What is glycolyse?

Answer 16

Dégradation du glucose pour faire de l’énergie
Glycolyse
* Dans le cytosol
Cycle de Krebs
* Dans la mitochondrie

Question 17

What does glycolysis lead to?

Answer 17

Glucose -> 2 pyruvate + 2 ATP + 2 NADH

Question 18

Steps in glycolysis: (3 key ones)

Answer 18

• Synthèse du** glucose-6-phosphate** (étape 1)
  Enzyme: Hexokinase
  Input: Glucose
  Output: glucose-6-phosphate
• Synthèse du fructose-1,6-diphosphate (adding another phosphate) (étape 3)
  Enzyme:** PFK-1**
  Input: fructose 6 phosphate
  Output: fructose 1,6 di phosphate
• Synthèse du pyruvate et 2 ATP (étape 10)
  Enzyme: Pyruvate Kinase
  Output: pyruvate + 2 ATP

Question 19

Which of the steps in glycolysis is the key point of control

Answer 19

• Synthèse du fructose-1,6-diphosphate (adding another phosphate) (étape 3)

Question 20

Regulation of glycolysis:

Exam quesiton

Answer 20

Concentration de glucose (stimulation par le substrat)

Concentration d’ATP
* Inhibition par [ATP] élevées:

Insuline stimule la glycolyse

Fructose-2,6-diphosphate stimule glycolyse (Exam quesiton)