proteins 3

Question 1

what is the Gibbs free energy equation

Answer 1

G= H-TS
H= enthalpy
S= entropy
T= temperature in K

Question 2

what is Gibbs free energy

Answer 2

amount of energy available to do work

Question 3

what time of reaction is it if Gibbs free energy is positive or negative

Answer 3

positive - endergonic
negatie - exergonic

Question 4

what are the standard conditions

Answer 4

• 1 molar concentrations
• 1 atm
• 25 degrees of 298 k
• pH7

Question 5

what is the equilibrium constant equation

Answer 5

Keq= product concentration / reactant concentration

Question 6

link Keq to the Gibbs free energy equation

Answer 6

G= G(standard free energy) + RTInKeq
simplified to G= -R x Tx InKeq

Question 7

if the standard reduction potential is more positive it means…

Answer 7

• stronger oxidising agent - electron acceptor
• weaker reducing agent

Question 8

if the standard reduction potential is more negative it means…

Answer 8

• weaker oxidising agent
• stronger reducing agent

Question 9

how does the standard electrode potential work

Answer 9

• reference cell = 0 volts
• electrons transferred through agar bridge and wire
• electron direction depends on relative redox power
• initial voltage taken at beginning of experiment when concentration is 1 mole

Question 10

what does epinephrine do in the body and where is it from

Answer 10

• from adrenal medulla and nerve endings
• used in liver for glycogenolysis and fat breakdown

Question 11

where is glucagon from and what does it do in the body

Answer 11

• from pancreatic alpha cells
• used in liver for glucogenolysis
• used in adipose for triacylglycerol breakdown

Question 12

where is cortisol from and what does it do in the body

Answer 12

• from adrenal cortex
• used in muscle and adipose for insulin resistance
• increases liver gluconeogenesis

Question 13

how is insulin released into the blood

Answer 13

1) glucokinase repsons to glucose in glycolysis
2) ATP produced in mitochondria
3) ATP-sensitive potassium channels close
4) change across membrane potential
5) calcium gates open
6) insulin vesicles fuse with membrane
7) insulin released into blood

Question 14

what causes primary lactase deficiency

Answer 14

• genetic fault of MCM6 regulator at LCT
• less reliant on milk so decreased expression

Question 15

what causes secondary lactase deficiency

Answer 15

• problems with small intestine eg. infections, crohns disease
• have lactose free products, extra calcium and vitamin D and lactase substitutes

Question 16

what does SGLT1 transporter do

Answer 16

• glucose and galactose
• against concentration gradient
• Na+ symporter
• from intestinal lumen to epithelial

Question 17

what does GLUT5 transporter do

Answer 17

• fructose
• inefficient
• intestinal lumen to epithelial

Question 18

what soda GLUT2 transporter do

Answer 18

• glucose , galactose and fructose
• epithelial to capillary

Question 19

what causes a GLUT 4 deficiency and what are the symptoms

Answer 19

• mutation in SLC2A4 in muscle and fat cells
• causes type 2 diabetes
• high blood sugar, insulin release stimulated, reduced glucose uptake

Question 20

what causes a GLUT 2 deficiency and what are the symptoms

Answer 20

• mutation of SLC2A2 in liver and pancreatic B cells
• causes type 2 diabetes
• fanconi-bickel syndrome - autosomal recessive - impaired glucose - glycogen accumulation and renal dysfunction

Question 21

what causes a GLUT1 deficiency and what are the symptoms and treatment

Answer 21

• mutation in SLC2A1 - autosomal dominat
• first month of life, nervous system disorder, small head, frequent seizures, developmental delay
• treatment of ketogenic diet - high fat, moderate protein and low carbs

Question 22

what causes a SGLT1 deficiency and what are the symptoms

Answer 22

• murrain in SLC5A1
• in infancy
• severe diarrhoea, weight loss, mild glucosuria, kidney stones