Week 5 Flashcards
(147 cards)
1
Q
What is catabolism ?
A
The process by which complex substances are degraded into simpler molecules.
2
Q
What is anabolism ?
A
Processes involved with the synthesis of complex organic molecules.
Net input of energy required.
3
Q
Describe catabolism in terms of chemical energy.
A
There is a net release of energy during catabolic processes.
4
Q
What is required for anabolic processes to occur?
A
Net input of energy.
5
Q
Define Glycolysis.
A
Releasing energy via the breakdown of glucose into pyruvate.
6
Q
Outline the net production of ATP during Glycolysis per molecule of Glucose.
A
2 ATP used, 4 made = +2
7
Q
Outline the net production of NAD+ during Glycolysis per molecule of Glucose.
A
2 used, 0 made = -2
8
Q
Outline the net production of NADH during Glycolysis per molecule of glucose.
A
0 used, 2 made = +2
9
Q
Outline the net production of Pi during Glycolysis per molecule of Glucose.
A
2 used, 0 made = -2
10
Q
What is used to reduce NAD+ to NADH during glycolysis?
A
GAPDH
11
Q
What does GADPH stand for ? (Enzyme)
A
GLyceraldehyde-3-phosphate dehydrogenase
12
Q
Why must NADH be reoxidised to allow glycolysis to continue?
A
There is only a small supply of NAD+ in the cellular cytoplasm
13
Q
Where in the cell is NAD+ found?
A
Cytoplasm
14
Q
What must occur for glycolysis to continue?
A
There is only a small supply of NAD+ in the cytoplasm of cells so NADH must be re-oxidised to NAD+ to allow glycolysis to continue.
15
Q
Define fermentation.
A
An energy yielding metabolic pathway with no net change in oxidation state of products compared to substrates.
16
Q
What is required for the conversion of pyruvate to lactate?
A
NADH + H+
17
Q
During the conversion of Pyruvate, H+ and NADH must be inputted, what are they converted to?
A
NAD+
18
Q
What is required for the conversation of pyruvate to acetaldehyde and what is this converted to?
A
H+
Converted to CO2
19
Q
What is required fort he conversion of Acetaldehyde to Ethanol and what is this converted to ?
A
NADH + H+
Converted to NAD+
20
Q
What is the product of homolactic fermentation of pyruvate?
A
Pyruvate
21
Q
In what organisms does homolactic fermentation occur?
A
Animal cells and lactic acid bacteria
22
Q
In what organisms does alcoholic fermentation occur?
A
Yeast
23
Q
What is the product of alcoholic fermentation of pyruvate?
A
Ethanol
24
Q
How does anaerobic glycolysis differ from aerobic glycolysis ?
A
Anaerobic Glycolysis forms Pyruvate, however the pyruvate cannot be reduced so there is no net oxidation of glucose.
25
What type of muscles is lactate produced by?
Active skeletal muscles
26
How does the rate of glycolysis compare to the rate of the krebs cycle ?
Glycolysis is faster
27
What enzyme catalyses the reduction of Pyruvate to lactate using NADH?
Lactate dehydrogenase
28
Briefly outline the process of alcoholic fermentation.
Involves cleavage of pyruvate to form acetaldehyde and carbon dioxide. The acetaldehyde is then reduced to ethanol using alcohol dehydrogenase.
29
What enzyme is used to reduce acetaldehyde to ethanol?
Alcohol dehydrogenase
30
What substances, other than glucose, can be used in the process of glycolysis?
Dietary carbohydrates (Lactose, maltose and sucrose), intracellular carbohydrates (Glyocgen) and metabolism of fats (Glycerol).
31
What are the 2 main roles of glycolysis ?
To produce ATP by degenerating glucose.
To provide substances that aid the synthesis of cellular components.
32
What must be regulated for the glycolytic pathway to occur in a controlled manner?
Hexokinase, phosphofructokinase and pyruvate kinase.
33
What is the required mass of glucose in the brain per day?
120g
34
What is the required mass of glucose in the bodily fluids per day ?
20g
35
What is the range of the mass of glycogen in the liver per day?
80-160g
36
What is the range of the mass of glycogen in the skeletal muscles per day?
280-800g
37
Define Gluconeogenesis.
The conversion of pyruvate to glucose via a metabolic pathway.
38
What are the primary gluconeogenetic tissues of the body?
Liver and kidneys
39
Name the tissues that synthesise glucose.
Liver, kidney cortex, kidney medulla
40
Name tissues that use glucose as their primary energy source.
```
Brain tissue
Nervous tissue
Muscles
Erythrocytes
Testes
```
41
How many steps of glycolysis must be bypassed during gluconeogenesis ?
3
42
What is the first bypass step of gluconeogenesis ?
The conversion of pyruvate to phosphoenolpyruvate.
43
Outline bypass step 1 of the gluconeogenesis reaction (conversion of pyruvate to phosphoenolpyruvate).
Pyruvate is converted to oxaloacetate by pyruvate carboxylase. The oxaloacetate is then converted into phosphoenol-pyruvate by phosphoenolpyruvate carboxykinase.
44
Write out the reaction of the conversion of pyruvate to oxloacetate.
Pyruvate + CO2 + ATP + H20 = Oxaloacetate + ADP + Pi + 2H+
45
What enzyme is required for the conversion of pyruvate to oxaloacetate?
Pyruvate carboxylase
46
What enzyme is required for the conversion of oxaloacetate to Phosphoenol pyruvate?
Phosphoenolpyruvate carbxykinase
47
Write out the reaction of the conversation of Oxaloacetate to Phosphoenol pyruvate.
Oxaloacetate + GTP =
| Phosphoenol Pyruvate + GDP + CO2
48
What is the second step of bypass in Gluconeogenesis ?
Conversion of Fructose-1,6-bisphoshate to Fructose-6-phoshate.
49
What enzyme is required in bypass 2 of gluconeogenesis (the conversion of Fructose-1,6-biphosphate to Fructose-6-phosphate)?
Fructose-1,6-biphosphatase
50
Write out the reaction of bypass 2 of gluoneogenesis (conversion of Fructos-1,6-biphospahte to Fructose-6-phosphate).
Fructose-1,6-biphosphate +H2O - Fructose-6-phosphate +Pi
51
What is bypass 3 step of gluconeogenesis?
The conversion of Glucose-6-phosphate to Glucose.
52
What enzyme is required in bypass 3 of gluconeogenesis (Conversion of Glucose-6-phosphate to Glucose)?
Glucose-6-phosphatase
53
Write out the reaction of bypass 3 of gluconeogenesis (conversion of glucose-6-phosphate to Glucose)
Glucose-6-phosphate +H2O - Glucose + Pi
54
Pyruvate carboxylase, the first enzyme in Gluconeogensis, requires what to work?
Vitamin B7 and Biotin cofactor
55
What cofactor does Pyruvate carboxylase require to work?
Biotin
56
What vitamin does pyruvate carboxylase require to work?
Vitamin B7
57
What non-carbohydrate precursors can be used for glucose synthesis?
Amino acids, glycerol and lactate
58
What is yielded by the hydrolysis of triacylglycerol?
Glycerol and fatty acids
59
What type of species can convert fatty acids into Glucose.
Animals Can't
| Plants can
60
By what process is Glucose synthesised from lactate ?
The cori cycle
61
What is the purpose of the 'Cori cycle'?
Synthesising Glucose from Lactate
62
Where does the Cori cycle occur?
Skeletal muscles, blood and liver
63
Where must lactate produced by glycolysis be transported to to allow re-synthesis of glucose?
Liver
64
What regulates rate of glycolysis ? (generally)
The availability of glucose
65
What regulates rate of gluconeogenesis? (generally)
Precursor availability
66
What stimulates Phosphofructokinase?
High levels of AMP
67
What is AMP?
Adenosine monophosphate
68
What activates Phosphofructokinase
Fructose-2,6-Biphosphate
69
What inhibits phosphofructokinase?
High levels of ATP and/or Citrate
70
What inhibits Fructose-1,6-Biphosphate?
High levels of AMP or Fructose-2,6-biphosphate.
71
What stimulates Fructose-1,6-biphosphate?
High levels of citrate
72
What activates pyruvate kinase?
Fructose-1,6-Biphosphate
73
What inhibits pyruvate kinase ?
High levels of ATP or alanine
74
What inhibits Pyruvate carboxylase?
High levels of ADP
75
What activates Pyruvate Carboxylase?
High levels of Acetyl- CoA
76
What inhibits Phosphoenolpyruvate carboxylase?
High levels of ADP
77
How does insulin affect genes encoding for the proteins of glycolysis?
Stimulates expression of these genes
78
How does insulin affect glycolysis ?
Causes glycolysis to occur
79
How does insulin affect gluconeogenesis and how does it do this?
Inhibits gluconeogenesis by turning off phosphoenolyruvate carboxykinase.
80
How does glucagon affect genes encoding for proteins of glycolysis?
Inhibits these genes
81
How does glucagon affect glycolysis.
Inhibits glycolysis
82
How does glycagon affect glyconeogenesis an how does it do this?
Stimulates glyconeogenesis by switching on expression of phosphoenolpyruvate and Fructose-1,6-biphosphatase.
83
Draw a diagram showing the full process of gluconeogenesis.
In notes
84
Draw a diagram showing he full process of glycolysis.
In notes
85
Describe the structure of saturated fatty acids at 22 degrees celcius
Waxy solids
86
Describe the structure of unsaturated fatty acids at 22 degrees celcius
Liquid
87
What are cis fatty acids?
Atoms are orientated on the same vertical side of a double carbon bond.
88
What are trans fatty acids?
Atoms are orientated on opposite vertical sides of the double carbon bond
89
How does length of a hydrocarbon chain affect melting point and explain why
As length of the hydrocarbon chain increases, melting point of the fatty acid increases as the number of van Der walls interactions between neighbouring tails increases.
90
How does saturation of a fatty acid affect its melting point?
The more saturated a fatty acid is, the higher its melting point.
Whereas the more double carbon bonds and therefore the more unsaturated a fatty acid is, the lower its melting point.
91
What are the key roles of Triacylglycerols?
Fatty acid storage in adipose tissue
Major energy storage and insulation.
Transport of dietary and synthesised fatty acids around the body via protein complexes.
92
What do Triacylglycerols to transport fatty acids around the body?
Protein complexes
93
Are Triacylglycerols hydrophobic or hydrophilic?
Hydrophobic
94
Define metabolism
Entire network of chemical reactions in living cells
95
Define metabolites
Small intermediates in degradation or biosynthesis of biopolymers
96
What type of reactions take place in anabolic reactions?
Reduction reactions
97
Do catabolic or anabolic reactions require energy?
Anabolic
98
What are anabolic reactions responsible for?
Synthesis of compounds for cellular growth and reproduction.
Producing simple metabolites.
Biosynthesis of larger molecules.
99
Define catabolism
Degradation of larger molecules to liberations smaller molecules and energy.
100
What type of reactions occur during catabolic reactions?
Oxidative reaction
101
Are anabolic reactions oxidative or reductive?
Reductive
102
Are catabolic reactions oxidative or reductive?
Oxidative
103
Do catabolic reactions use or release energy?
Release
104
What type of reactions do all cells carry out as normal cellular reactions?
Catabolic reactions
105
What are amphibolic reactions?
other anabolic and catabolic reactions occurring.
106
What are the products of catabolic reactions ?
Hydrogen atoms and electrons
ATP
Carbon skeletons and carbon dioxide
Nitrogen
107
What must be catabolism for nitrogen to be produced?
Amino acids
108
What are the hydrogen atoms and electrons produced by catabolism used for ?
Oxidative phosphorylation and reduction in biosynthesis
109
By what method is ATP produced by catabolism?
Substrate-level phosphorylation
110
What is a metabolic pathway?
A series of reactions where the product of one reaction becomes the substrate for another.
111
Why is it often difficult to find the start and end of metabolic reactions?
The product of one reaction is often used as the substrate for the next reaction
112
What are the 2 eyes of metabolic pathway?
Linear
| Circular
113
What are linear metabolic reactions?
A series of reactions in sequence with one another
114
What are circular metabolic reactions?
A series of reactions which form a repeated cycle
115
What is the average energy for the synthesis of glucose from carbon dioxide and water ?
29000KJmol^-1
116
Can energy transfer efficiency be 100%?
No
117
What are the 2 methods of metabolic regulation?
Feedback inhibition
| Feed forward activation
118
Define oxidation.
Loss of electrons
119
Define reduction.
Gai of electrons
120
What are autotrophs
An organism capable of self-nourishing by using inorganic ion materials as a source of nutrients and using photosynthesis or chemosynthesis as a source of energy.
121
What are the 2 categories of autographs?
Photoautotrophs
| Chemoautotrophs
122
What are photoautotrophs?
Produce energy by photosynthesis using carbon dioxide
123
What are chemoautotrophs?
Produce energy by oxidising inorganic molecules and using carbon dioxide as a carbon source
124
What are heterotrophs?
Organisms which cannot manufacture their own food source by carbon fixation and therefore derive their intake of nutrition from organic carbon sources.
125
What are the 2 categories of heterotrophs?
Photoheterotrophs
| Chemoheterotrops
126
What are photoheterotrophs?
Photosynthetic organisms that require an organic compound as a carbon source
127
What are chemoheterotrophs?
Non-photosynthetic organisms which require organic molecules such as carbon as a carbon source.
128
What is the difference between photoheterotrophs and chemoheterotrophs?
Photoheterotrophs are photosynthetic and chemoheterotrophs are not.
129
Where is ATP synthesised in bacteria?
Plasma membrane
130
Where is ATP synthesised in Eukaryotes?
Mitochondrial membrane
131
What factors control energy release?
Electrostatic repulsion
Solution effects
Resonance stabilisation
132
What is electrostatic repulsion?
The repulsion between particles with the same charge.
133
How does electrostatic repulsion change once a molecule is hydrolysed?
Reduced
134
Are the products of ATP more or less stable than ATP?
More
135
What is resonance stabilisation?
Resonance allows for delocalisation in which the overall energy of a molecule is lowered. This is the case because the electrons occupy a greater volume.
136
How does resonance affect the stability of a molecule?
Makes them more stable
137
Write out the reaction between GMP and ATP
GMP + AT - GTP + ADP
138
Write out the reaction between GDP and ATP
GDP + ATP - GTP + ADP
139
Write out the reaction between AMP and ATP
AMP + ATP - 2ADP
140
Write out the reaction between AMP, ATP and Pi
AMP + ATP + 2Pi - 2ATP + 2H20
141
Where is the energy used in anabolic reactions released from?
Catabolic reactions
142
What is the energy released by catabolic reactions used for?
Growth and development
| Anabolic reactions
143
What are the benefits of feedback inhibition of metabolism to an organism?
Helps an organism conserve energy without disrupting the balance of metabolic chemical reactions.
144
Outline how feedback inhibition of metabolism works.
The final product in a pathway will inhibit an earlier step in the process. Once the presence of this final product goes above a certain concentration, the reaction pathway will be slowed.
145
What pathway type is feedback inhibition of metabolism?
Linear
146
What is feed forward activation of metabolic regulation?
Process used in metabolic pathways by which an early product in the pathway activates or catalyses future reactions.
147
What pathway type is feed forward activation of metabolic activation?
Either liner or branched
