Lectures 1-5 Flashcards
(211 cards)
1
Q
Definition of bioenergetics
A
The study of the transformation of energy in living organisms
2
Q
What is metabolism? (Definition)
A
The sum of all chemical reactions in the body
3
Q
What are the two types of metabolic reaction?
A
Catabolic and anabolic
4
Q
What is a catabolic reaction?
A
The breakdown/degradation of molecules
When molecules are broken down (e.g., carbs/fat and protein) they release energy
5
Q
What is an anabolic reaction?
A
Synthesis of new molecules
The energy released from anabolic reactions can be used to build new molecules
6
Q
Examples of catabolic pathways
A
Proteolysis
Lipolysis
Glycolysis
Glycogenolysis
Anything ending in lysis
7
Q
Examples of anabolic pathways
A
Protein synthesis
Lipogenesis
Gluconeogenesis
Glycogenesis
Anything really ending in genesis/sis
8
Q
How are catabolic and anabolic pathways regulated?
A
Substrate supply - food and other compounds
Hormonal control - switch on or turn off pathways and alter enzyme activity
Allosteric control - speed or slow enzyme activity
9
Q
What is our body fueled by?
A
Adenosine Triphosphate (ATP)
10
Q
What is ATP?
A
The energy currency of the cell
ATP is what we use to fuel all our metabolic reactions
11
Q
What is the link between food and ATP?
A
The food we consume is digested and used to generate ATP
12
Q
Look at structure of ATP
A
Lecture 1, slide 19
13
Q
How do we generate ATP?
A
Look at on recap lecture 1, slide 21
14
Q
Look at enzyme substrate thing
A
Recap, lecture 1, slide 22
15
Q
When an enzyme is attached to the substrate what does it form?
A
It forms a complex
16
Q
What does the enzyme catalyse the formation of after the enzyme has attached to the substrate and formed a complex?
A
The formation of a product
17
Q
Interaction and specificity with enzymes can be explained in two ways, what are they?
A
Lock and key
Induced fit
18
Q
What is lock and key (enzyme interaction and specificity)
A
The binding site has a complementary shape to the substrate
19
Q
What is induced fit (enzyme interaction and specificity)
A
Contact between part of the binding site and the substrate induces a change in the shape of the active site to bind to the substrate
20
Q
Look at examples of lock and key and induced fit
A
Lecture 1, slide 24
21
Q
What is allosteric control? (Listen on recap)
A
Refers to a type of enzyme regulation involving the binding of a non-substrate molecule, known as the allosteric effector, at locations on the enzyme other than the active site
22
Q
What is allosteric inhibition? (Listen on recap) (lecture 1, slide 27)
A
Where the allosteric effector binds to the allosteric site, causing the enzymes active site to alter, meaning that the enzyme cannot bind to the substrate
23
Q
What is allosteric activation? (Listen on recap) (lecture 1, slide 27)
A
Where the allosteric effector binds to the allosteric site, causing the enzymes active site to change so that the enzyme is able to bind to the substrate
24
Q
What is a good example of one of the most important allosteric regulatory effects?
A
When we go from a stand still to a sprint within milliseconds, (we require a huge amount of energy in a short period of time)
The active site enzymes are not quick enough to provide the energy, so the allosteric enzymes take charge
25
How is enzyme activity affected?
Substrate Concentration
pH
Enzyme concentration
Temperature
26
How does substrate concentration impact enzyme activity?
Increases and augments reaction rate up to a point
27
How does pH impact enzyme activity?
Can change active site structure and alter affinity for substances
28
How does enzyme concentration impact enzyme activity?
Increase can augment reaction rate because more active binding sites available (McLaren & Morton, 2011)
29
How does temperature impact enzyme activity?
Increase augments enzyme activity until ~37.5 degrees
30
How much ATP is stored in the muscle tissue?
40-50 grams
31
How quickly is all of the ATP that is stored in the muscles used up?
2-4 seconds
32
What are the anaerobic energy sources that can be used to resynthesise ATP?
Lecture 1, slide 31
ATP
Phosphocreatine
(PCr) (check if this is just phosphocreatine)
Anaerobic glycolysis
33
What are the aerobic energy sources that can be used to resynthesise ATP?
Aerobic glycolysis
Carbohydrate oxidation
Fat oxidation
Protein breakdown
34
Look at what you really need to know slide
Lecture 1, slide 32
35
What is an atom?
Building blocks of all things (matter)
36
What is an element?
A pure substance which cannot be broken down into a simpler substance by a chemical reaction. It contains only one type of atom
37
How many elements are there on the periodic table?
Over 100 different elements
38
96% of body mass contains 4 elements, what are they?
Oxygen (65%)
Carbon (18%)
Hydrogen (10%)
Nitrogen (3%)
39
What do all organic compounds contain?
Carbon and hydrogen
40
Are protons positively or negatively charged?
Positive
41
Are electrons positively or negatively charged?
Negative
42
What is in the centre of an atom?
Protons and neutrons
43
Where are the electrons in relation to an atom?
They are around the nucleus
44
The electrons in the “cloud” are not random but are organised into a series of layers called what?
Shells and sub-shells
45
When is an atom most stable?
When it’s outermost shell or sub-shell is completely full of electrons
46
Electrons are shared in one of two ways, what are they?
Sharing electrons
Giving an electron
47
In terms of sharing electrons, how does “sharing electrons” work?
Where the atom combines with a new atom, leading to the formation of a covalent bond
48
In terms of sharing electrons how does “giving an electron” work?
The atom gives an electron to another atom / receives an electron from another atom. This leads to formation of an ionic bond
49
What is an ion?
An atom becomes an ion when it’s charge has been altered by losing or gaining an electron
50
What is it called when a normal atom becomes an ion?
Ionisation
51
Negatively charged ions are known as what?
Anions (electron gain)
52
Positively charged ions are known as what?
Actions (electron loss)
53
What is a large molecule called?
Macro...
54
What is a small molecule called?
Micro...
55
What is a molecule?
Contains two or more atoms chemically joined together
56
What is a compound?
A molecule composed of atoms from two or more different elements
57
What are the two types of compounds?
Organic
Inorganic
58
What is the difference between organic and inorganic compounds?
Organic compounds contain carbon, inorganic compounds contain no carbon
59
To see how atoms form the compounds we eat
Look at slide 11, lecture 2
60
What are chemical bonds?
They are how atoms join together
61
How are bonds formed?
Through the action of electrons, which are donated/taken from one molecule to another
62
What does ionic bond formation depend on?
Electronegativity (the attraction of an atom for electrons)
63
Look at how electronegativity of atoms vary
Slide 13, lecture 2
64
When do ionic bonds form?
When the difference in electronegativity between two atoms is very high >1.7
(The atom with the highest electronegativity pulls one or more electrons completely away from the other atom)
65
What are covalent bonds?
Sharing electrons with another atom
66
Look at covalent bond formation on recap
Slide 15-17 lecture 2
67
Go on recap
For slide 18 lecture 2
68
What is a polar covalent bond?
A bond in which one part of the molecule is more charged than the other
The electrons are not shared equally
These molecules are hydrophilic - excellent solvents
69
What is a non-polar covalent bond?
A bond in which the charged of each molecule are equal
The electrons are shared equally
Atoms from the same element are non-polar
70
What is the order of strength for covalent, ionic and hydrogen bonds?
Covalent is stronger than ionic, ionic is stronger than hydrogen
71
The breaking or making of a bond is called what?
A chemical reaction
72
When a bond breaks/forms and a chemical reaction occurs, what is produced?
Energy
73
So talking, walking etc is simply what?
Bonds between atoms being split or joined
74
There are several different types of chemical reactions in the body, what are they?
Check recap slide 21 to see which ones we need to know, lecture 2
75
Recap for slide 22
Lecture 2
76
What are redox reactions extremely important in?
Energy production, particularly in long duration exercise when ATP turnover is high
77
Look at slide 23 lecture 2
For most common redox reaction
78
When a molecule is oxidised what happens? In terms of gain/loss of electrons
It loses electrons
79
When a molecule is reduced what happens? In terms of gain/loss of electrons
It gains electrons
80
What does OIL RIG stand for?
Oxidation
Is
Losing electrons
Reduction
Is
Gaining electrons
81
Cell structure
Lecture 2 slide 26
82
What is the cytoplasm?
The fluid in the cell - often referred to as everything expect the nucleus
83
What is cytosol
The fluid portion (of cytoplasm) & several important energy generating reactions take place here
84
What is mitochondria?
An organelle - the energy currency of the cell (check this)
85
What does the mitochondria generate?
More ATP than any other part of the cell in the matrix
86
What does exercise do to mitochondria?
Increases the size of mitochondria in the cell and also the number it contains
87
What is the cell membrane?
The gatekeeper of the cell
Surrounds the whole cells
Lipid bilateral - phospholipid, glycolipid, cholesterol
88
Look at what you really need to know
Slide 30 lecture 2
89
Structure of ATP etc
Lecture 3 slide 3
90
Slide 5
Lecture 3
91
Contribution of different energy systems to overall energy production
Slide 6 lecture 3
92
What is glycolysis?
The metabolic pathway that we use to turn glucose into energy
93
Can glycolysis generate energy without the need for oxygen? (Be anaerobic)
Yes
94
Very high intensity exercise requires what? (In terms of ATP)
An extremely high rate of ATP generation
95
Why are aerobic metabolic pathways (to create O2) not used very high intensity exercise?
The rapid demand in ATP means there is not enough time to rely on aerobic metabolic pathways
96
What molecule does high intensity exercise rely on?
Phosphocreatine
97
How much phosphocreatine is stored in the muscles?
120g
98
What is phosphocreatine degradation?
The breakdown of PC to generate ATO
99
Creative kinase reaction
Slide 10 lecture 3 - recap
100
What enzyme catalyses the reaction of ADP -> ATP + creatine
Creatine kinase
101
How long can PCr only fuel the body for?
Approximately 10-14 seconds of exercise
102
Do PCr concentrations ever reach 0?
No
103
Why do PCr concentrations never reach 0?
Your body has a fail safe mechanism to avoid this
104
What foods contain creatine?
Egg, red meat, fish (eg salmon)
105
How does creatine supplement work?
It increases intramuscular stores of creatine. This should theoretically improve performance because these stores will not then be depleted so quickly
106
The need for rapid energy creates what?
An oxygen deficit
107
How long does it take to fully resynthesise PCr stores?
3-5 minutes
108
What does the resynthesis of PCr require?
Oxygen and blood flow
109
What happens to PCr resynthesis when blood flow and therefore oxygen supply is blocked?
PCr resynthesis is inhibited
110
Is the aerobic energy system always contributing?
Yes, very small amounts at times but yes
111
What is the contribution of the aerobic energy system during 10 seconds of exercise or less?
3%
112
What is the contribution of the aerobic energy system during 30 seconds of exercise or less?
15%
113
What is the contribution of the aerobic energy system during 60-90 seconds of exercise or less?
55%
114
What is the contribution of the aerobic energy system during 60-90 seconds of exercise or more?
70%
115
What adaptations does sprint training obtain?
Increase glycolysis utilisation
Increase enzyme activity
Increase transport proteins
116
What energy sources does high intensity intermittent exercise (football) use?
Both aerobic and anaerobic
117
What happens to the contribution of anaerobic glycolysis after as little as 4 or 5 all out 6 second sprints?
It starts to fall
118
Recap
Slide 23 lecture 3
119
Recap
Lecture 3 slide 24 + 25 + 26 + 27
120
What causes metabolic fatigue during high intensity intermittent sports?
```
Acidosis
Impaired calcium function
Build up of H+
Reactive oxygen species (recap wtf it is)
Increase in extracellular potassium
Muscle glycogen depletion
PCr depletion
```
121
Do energy systems ever work in isolation? If not then what changes?
No
Merely the contribution of each energy system
122
What you really need to know slide
Lecture 3
123
What is glycolysis?
The breakdown of glucose to produce energy
124
What does glycolysis involve?
The breaking apart a 6 carbon molecule of glucose to a 3 carbon molecule of pyruvate
125
Can every cell in the body generate energy from glycolysis?
Yes
126
Why is glycolysis often seen as the emergency energy pathway?
Because energy can be generated rapidly
127
In cells that don’t have mitochondria, is glycolysis the only energy pathway?
Yes
128
Glycolysis is primarily regulated by two main hormones, what are they?
Insulin (activator)
| Glucagon (inhibitor)
129
Can glycolysis be anaerobic and aerobic?
Yes
130
During sever intensity exercise, or when the PCr system has been depleted, we are heavily reliant on what to provide energy?
Anaerobic glycolysis
131
How many reactions (stages) does glycolysis have?
10
132
Reactions 1-5 for glycolysis are termed what? And why?
The investment phase. This is because here ATP is used
133
Reactions 6-10 for glycolysis are termed what? And why?
The pay off phase. This is because ATP is generated
134
Where does anaerobic glycolysis take place?
The cytosol
135
Slides 7-10, lecture 4
Stages of glycolysis
136
Large amounts of pyruvate increases what?
Lactic acid production
137
If lots of pyruvate creates lots of lactic acid, then extensive reliance on anaerobic glycolysis produces what?
Large amounts of lactic acid
138
Slide 12
Lecture 4
139
What is glycogenesis?
Formation of new glycogen
140
What is glycogenolysis?
Breakdown of glycogen
141
When is glycogenesis most likely to occur?
When there is glucose in the cell and insulin has been secreted
142
Process of elongation
Slide 16, lecture 4
143
Glycogen can only be stored as what?
Branches of glucose polymers
144
Glucose polymers have several branches, what does this mean?
That they can be broken down to glucose molecules rapidly
145
What happens when 11 or more glucose chains have been formed?
They can start to branch
146
Slide 18 lecture 4
Recap
147
When does glycogenolysis occur?
During times such as fasting
148
During glycogenolysis what happens to glucose?
Glucose starts to be removed from the glycogen chain via phosphorolysis
149
During glycogenolysis, when glycogen is removed from the glycogen chain what are they broken down into?
10% are broken down into glucose
90% are broken down to glucose-1-P
150
What is an important enzyme in glycogenolysis?
Glycogen phosphorylase - assumes to be rate limiting step
151
Slide 21-23, lecture 4
Recap
152
What is the whole point of glycogenolysis?
To convert branches glycogen molecules into straight ones
153
What happens to glycogenolysis in skeletal muscle during high intensity exercise? (Eg 800m)
It is significantly upregulated
154
When is glycogenesis activated?
After a CHO meal
155
What does glycogenesis form?
Forms new glycogen for storage?
156
How does glycogenesis form new glycogen for storage?
By adding glucose molecules together to form branches
157
When is glycogenolysis activated?
When fasting/high intensity exercise
158
What does glycogenolysis do?
Breaks down glycogen stores for energy
159
How does glycogenolysis break down glycogen stores for energy?
By breaking off glucose molecules one by one to be used in glycolysis
160
What happens to glycogenolysis in terms of exercise intensity
It increases with exercise intensity
161
How quickly can glycogenolysis be activated?
Within 1 second of the onset of exercise
162
What you really need to know slide
Slide 28 lecture 4
163
What does TCA stand for in the TCA cycle?
Tricarboxylic acid
164
What is the TCA cycle also known as?
The Krebs cycle
165
How many reactions does the Krebs/TCA cycle involve?
8
166
Where do the 8 reactions in the TCA/Krebs cycle take place?
The mitochondria (think it’s matrix of...)
167
Is the TCA/Krebs cycle aerobic/anaerobic?
It is an aerobic process that requires O2
168
What are the functions of the Krebs/TCA cycle?
Oxidation pathway for CHO/lipids/proteins
Generates energy or intermediates (NADH) to be used in the electron transport chain for energy
Provides several precursor molecules for other metabolic pathways
169
What does the TCA/Krebs cycle start with?
Acetyl co-A
170
What can eventually form Acetyl co-A (what enters the Krebs/TCA cycle)
Glucose (CHO)
Triacyglycerides (fats)
Amino acids (proteins)
171
What is formed at the end of glycolysis (TCA/Krebs cycle bit) that can enter the mitochondria for conversion to...
Pyruvate
Acetyl-CoA
172
What is the reaction called where pyruvate is converted into Acetyl co-A?
The link reaction?
173
What are the products of the link reaction where pyruvate forms Acetyl co-A?
CO2
| Creates 1 NADH
174
What catalyses the link reaction of pyruvate to Acetyl co-A?
Pyruvate dehydrogenase (PDH)
175
What is pyruvate dehydrogenase?
It is a group of enzymes (not really important at this level)
176
Does PDH have both an active and inactive form?
Yes
177
What is the active form of PDH?
Non-phosphorylated
178
What is the inactive form of PDH?
Phosphorylated
179
What does PDH kinase do?
It is the enzyme that keeps PDH inactive
180
When is PDH kinase upregulated?
When energy in the cell is plentiful or demand is low
181
What is the role of PDH phosphatase?
It is the enzyme that activated PDH
182
When is PDH phosphatase activates?
When energy in the cell is low
183
During exercise what happens to PDH?
It is activated
184
What are magnesium and calcium in relation to PDH?
They are both allosteric regulators of PDH
185
When is PDH activated?
When energy in the cell is low
186
When is PDH inhibited?
When energy in the cell is plentiful
187
What does PDH activation activate?
The TCA/Krebs cycle via glycolysis
188
When we use PDH, which fuel source for energy are we becoming more reliant on?
Carbohydrate
189
What does it mean when NAD+ is reduced to NADH? (The same is true for FAD+ to FADH2)
It means that it gains an electron from the hydrogen
190
What are NADH and FADH2 essentially?
They are essentially electron carriers
191
Learn steps of the TCA/Krebs cycle
Lecture 5, slide 14
192
How many molecules of ATP are generated via the TCA/Krebs cycle?
1
At A-level it said 2?
193
What are the products of one cycle of the TCA/Krebs cycle?
1 ATP
3 NADH
1 FADH2
194
What happens to NADH and FADH2 after the Krebs/TCA cycle?
The go to the electron transport chain
195
Is the TCA/Krebs cycle an aerobic or anaerobic process?
It is an aerobic process
196
Several of molecules in TCA cycle can be used for other reactions
Lecture 5, slide 18-23
197
Look at what you need to know slide
Lecture 5, slide 34
198
Glycolysis is often seen as the ‘emergency’ energy pathway because it can generate energy rapidly:
True/False
True
199
Glycolysis:
A) Occurs in the mitochondria
B) Generates 8 ATP
C) Generates 2 NADH molecules
D) Is the primary energy pathway during a 10km race
C) Generates 2NADH molecules
200
Glycolysis has:
A) 10 reactions, 3 of which are irreversible
B) 8 reactions, none of which are irreversible
C) 10 reactions, 2 of which are irreversible
D) 10 reactions, none of them are irreversible
A) 10 reactions, 3 of which are irreversible
201
Gluconeogenesis is activated by hunger:
True/False
True
202
Glycogen is stored in the:
A) Liver only
B) Muscle, liver
C) Muscle, liver, adipose tissue
D) Liver, adipose tissue
B) Muscle, liver
203
Is Glycolysis an anaerobic or aerobic process:
A) Anaerobic
B) Aerobic
C) Both
D) Neither
C) Both
204
During high intensity exercise glycogenolysis is:
A) Inhibited
B) Upregulated
C) Unchanged
B) Upregulated
205
In glycogenolysis, which organ(s) convert glycogen to glucose?
A) Skeletal Muscle
B) Liver and Skeletal Muscle
C) Liver
D) Liver and adipose tissue
C) Liver
Double check
206
Pyruvate dehydrogenase (PDH):
A) Is inhibited by NAD+
B) Is active when phosphorylated
C) Is regulated by PDH kinase and PDH phosphatase
D) Catalyses the production of pyruvate from Acetyl co-A
C) Is regulated by PDH kinase and PDH phosphatase
207
What is glycogenesis?
The formation of glycogen from sugar
208
What is glycolysis
The breakdown of glucose by enzymes, releasing energy and pyruvic acid
209
What is gluconeogenesis?
The generation of glucose from non-carbohydrate carbon substrates
210
What is glycogenolysis?
The breakdown of glycogen into glucose
211
What is the structure of ATP?
Adenine-ribose-P-P-P
