Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Metabolism > Session 2-Energy,glycolysis,carbs and galactosaemia > Flashcards

Session 2-Energy,glycolysis,carbs and galactosaemia Flashcards

1
Q

Why are cell nutrients transported to body tissues?

A
  • Degraded to release energy
  • Used to synthesise cell components (NOT RBC)
  • Storage
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the characteristics of catabolic pathways?

A
  • Oxidative-releases H+ ions for reducing power

- Release energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the characteristics of anabolic reactions?

A
  • Reductive-use H+

- Use intermediate metabolites and energy produces by catabolism to drive the synthesis of cell components

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Creatine is used for a quick release of energy in muscles, for example. What enzyme catalyses this?

A

Creatine kinase

Creatine + ATP —> Creatine phosphate + ADP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What 4 molecules are known as high energy signals and why?

A
  • ATP, NADH, NADPH, FAD2H

- signal that the cell has ADEQUATE energy levels and reducing power is available for anabolism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

how are dietary polysaccharides hydrolysed?

A
  • Using glycosidase enzymes

- Releases glucose and maltose and leaves smaller polysaccharides (dextrins)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

where does hydrolysing of polysaccharides begin and end?

A

Begins with salivary amylase

Continues in duodenum with pancreatic amylase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Where does digestion of disaccharides occur?

A

-Duodenum and jejunum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what are the 3 major enzymes involved in digesting disaccharides?

A

-lactase, glycoamylase, sucrase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the minimum glucose requirement for a healthy adult per day?

A

-180g/day

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Which areas of the body require 40g and which 140g?

A

40g=tissues that only use glucose

140g=CNS that prefers glucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Is glycolysis activated in ALL tissues?

A

Yes!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What does glycolysis generate?

A

-ATP (anaerobically)
-NADH from NAD+
-intermediates for cell functions
-NO LOSS of CO2
-

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the difference between substrate level (SLP) and oxidative phosphorylation (OP)?

A
  • SLP- occurs if a reaction releases sufficient energy to allow the addition of phosphate onto ADP
  • OP- ATP generated from the oxidation of NADH and FADH2 (including the transfer of electrons and pumping of protons) Process generates electrochemical gradient which powers ATP synthase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is the net production number of ATP in glycolysis?

A

2 ATP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Which 3 steps are irreversible?

A

1,3 and 10

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What enzyme is used to catalyse step 1?

A

Hexokinase (glucokinase in liver)

glucose—>glucose-6-phosphate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What enzyme catalyses step 3?

A

PFK-1 (phosphofructokinase)

fructose 6-phosphate—>fructose 1,6-bisphosphate

19
Q

What enzyme catalyses step 10?

A

pyruvate kinase

phosphoenolpyruvate—>pyruvate

20
Q

what enzyme reduces pyruvate to lactate (lactic acid)?

A 
lactate dehydrogenase (LDH) 
NOTE: LDH increases NAD+ concn under anaerobic conditions for glycolysis to proceed
21
Q

what is the overall equation for the 11 steps of glycolysis, including the lactate step?

A

glucose+2Pi+2ADP –> 2lactate + 2ATP + 2H2O

22
Q

where do cell nutrients come from?

A
  • Diet
  • Synthesis in body tissues from precursors
  • release from storage in body tissues
23
Q

What concentration does lactate production have to exceed before it becomes a problem?

A

5mM-exceeds renal threshold and affects buffering capacity of plasma causing LACTIC ACIDOSIS

24
Q

What is glucose converted into at step 1 in glycolysis?

A

glucose 6-phosphate (ATP—>ADP)

25
What is the reaction in step 3 of glycolysis?
fructose 6-phosphate--->fructose 1,6-bisphosphate
26
what is the reaction in step 10 of glycolysis?
phosphoenolpyruvate---->pyruvate (ADP--->ATP)
27
what is the overall reaction of galactose metabolism?
galactose + ATP----> glucose-6-phosphate + ADP (continues to glycolysis)
28
What 2 enzymes when lacked cause galactosaemia (inability to utilise galactose)?
galactokinase and galactose-1-P-Uridyl transferase (GUT)
29
which enzyme deficiency in galactosaemia is more common?
uridyl-1-p-transferase
30
why is the absense of the transferase enzyme more serious?
-causes build up of galactose and galactose-1-phosphate(toxic in liver)
31
what happens when galactose accumulates in the blood?
- Galactose--->galacticol (using ALDOSE REDUCTASE) | - NADPH--->NADP+ (less reducing power now available)
32
how does cataracts form in the eye?
- disulphide bond formation (s-s) | - Changes and alters protein and thus its function
33
what else happens in the eye with increased galactose and galacticol levels?
-Raise in pressure (glaucoma) causing blindness
34
why does galactose-1-phosphate damage liver?
-hides Pi making it unavailable for ATP synthesis
35
what test can you do to see if someone is going to have an MI and why does this happen?
check blood creatine kinase levels-leak out of damaged cardiac myocytes (cells)
36
what is the breakdown product of creatine called?
creatinine
37
in which 3 ways is creatININE a useful clinical marker?
- excreted via kidneys - creatinine excretion per 24 hours is proportional to muscle mass (provides measure of muscle mass) - creatinine in urine is marker of urine dilution - indicator of renal function
38
Between glucose and pyruvate in glycolysis, name 6 important intermediates in between. Give roles for the 4th and 5th ones.
1. Glucose 6 phosphate 2. Fructose 6 phosphate 3. Fructose 1,6 bisphosphate 4. Glyceraldehyde 3 phosphate--->converts to dihydroxyacetone phosphate (DHAP) and then glycerol phosphate for TAG formation 5. 1,3 BPG (bisphosphoglycerate)--->converts to 2,3 BPG for HB O2 affinity regulation 6. Phosphoenolpyruvate
39
How much NADH is produced during glycolysis?
2
40
How much NADH is produced per pyruvate being oxidised to form acetyl CoA?
1
41
Monosaccharides are absorbed into tissues by facilitated diffusion using transport proteins called....
GLUT1-5
42
Why do RBCs go through the lactate pathway?
Cannot carry out TCA cycle or oxidative phosphorylation | Need to regenerate NAD+ by going through lactate pathway
43
What are the roles of glut 1 and 4 and where is glut 4 found?
Move glucose into cells | Glut 4 found in muscle and adipose tissue
44
Where is glut 2 found and what does it do?
Found in liver | Transfer glucose to blood from hepatocytes

Metabolism (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions