7: Harvesting Chemical Energy Flashcards Preview

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Flashcards in 7: Harvesting Chemical Energy Deck (40):
1

ATP powers cellular work – it is our energy currency.
The ______of ___to ___and inorganic _______releases energy

hydrolysis
ATP to ADP
phosphate

2

Anabolism definition
Catabolism definition

Anabolism: 'building up'
Catabolism: 'breaking down'

3

The ATP cycle: the transfer of energy between ______and
______molecules in the body, with ATP as the mediator

complex
simple
ATP

4

Fuel is needed to
generate ATP. Our major categories of fuel are:

• Proteins:
broken down to amino acids
• Fats:
broken down to simple fats
• Carbohydrates:
broken down to simple sugars
Which are then absorbed

5

Conversion of glucose to ATP is due to 4 main steps:

Glycolysis
Pyruvate oxidation
Citric acid cycle (or Krebs cycle)
Electron transport chain

6

Step 1: Glycolysis
Occurs where?
is oxygen needed?

cytosol
oxygen is not required

7

Glycolysis: The lysis of glucose
to produce _ _____ ________.
t)

two
pyruvate molecules

8

Glycolysis
two ATP are
invested in what phase?
(four ATP are
produced in what phase?
two ATP and 2NADH
are produced in what phase?

Energy investment phase
energy payoff phase
net

9

Step 2: Pyruvate oxidation to form _______ ____

Acetyl CoA

10

Pyruvate oxidation links glycolysis to the ___________
Occurs in the _______
is oxygen required?

citric acid cycle
mitochondrial matrix
required

11

Pyruvate oxidation
produces ______but produces 1 ______per pyruvate (or 2 per glucose) plus 1 _____

no ATP,
NADH
CO2

12

What process Results in :
2 ATP
2 FADH2
4 CO2
6 NADH
(per glucose molecule)

Step 3: Citric acid cycle

13

_______and ______are electron donors in the electron transport chain

FADH2
NADH

14

does Citric acid cycle require oxygen?
Where does it occur?

yes
matrix

15

define Substrate phosphorylation :

ATP is generated by the direct transfer of a
phosphate group to ADP

16

define Oxidative phosphorylation:

ATP is generated from the oxidation of NADH and
FADH2 and the subsequent transfer of electrons and pumping of protons

17

Glycolysis produces __________________
Pyruvate oxidation produces _________
Citric acid cycle produces ________________

2 net ATP per glucose
no ATP
2 ATP per glucose

18

the citric acid cycle completes the _______ __ _______ from glucose

extraction of energy

19

The Electron Transport Chain occurs where?
Does it require oxygen?

Occurs at proteins within the inner membrane
Requires oxygen

20

_____and _____are oxidised to
donate 1 or 2 electrons.
Electrons transfer from protein to-protein
along chain
At each transfer, each electron gives
up a small amount of ______ which enables ___ions to be pumped into
the intermembrane space
________ “pulls” the electrons down the chain, and is then the final electron acceptor where it is reduced
to _______

NADH and FADH2
energy , H+
Oxygen
water

21

The hydrogen ions in the _________space rush down
their concentration gradient (__________) through ATP
synthase.
This causes the “turbine” within ATP synthase to turn

intermembrane
chemiosmosis

22

The rotation of the ATP synthase turbine enables
the _________ of ___to generate ___

phosphorylation
ADP
ATP

23

chemiosmosis results in the production of what?

26 or 28 ATP

24

“fall” of _____down the chain enables movement of H+ ions into intermembrane space
generates a proton gradient which “drives” the ___________________

electrons
ATP synthase turbine

25

How many ATPs produced per second in one cell by cellular respiration?

10 million

26

Why 26 OR 28 ATP produced in electron transport chain & chemiosmosis?

Phosphorylation and redox reactions are not directly coupled, so have a ratio
rather than a straight number
Energy stored in the H+ gradient may be used solely to produce ATP or may be
split between making ATP and powering other mitochondrial processes.

27

Cellular respiration is versatile
Where can we derive energy other than just glucose.?

Fats, proteins and more
complex carbohydrates
Monomers enter glycolysis
and the citric acid cycle at
different points

28

P__________can be rate
limiting for glycolysis
it is inhibited by citrate and ATP

Phosphofructokinase

29

Homeostasis generally depends on ____________ mechanisms
but can be impacted on by _____________mechanisms

negative feedback
positive feedback

30

Homeostasis definition:

the maintenance of relatively constant conditions within physiologically tolerable limit

31

2 Hormones controlling blood
glucose:

Insulin:
Glucagon:

32

Insulin:
Produced by of ________ Islets of Langerhans in pancreas
• Function: promote _______ ______ into cells (for ATP
production or storage in liver)

beta cells
glucose uptake

33

Glucagon:
• Produced by ___________ of Islets of Langerhans in ________
• Function: Stimulates the _______ __ _________ to increase
blood sugar levels

alpha cells
pancreas
breakdown of glycogen

34

What happens if you lose the function
of insulin?

No glucose in cells
• No ATP from glucose
• No glycogen “for a rainy day”

35

Diabetes Mellitus definition

the ability to produce or
respond to the hormone
insulin is impaired

36

Diabetes Mellitus results in?

results in abnormal
metabolism of carbohydrates
and elevated levels of glucose
in the blood

37

Type 1 or insulin-dependent diabetes:

Body does not produce insulin, as beta cells of pancreas are destroyed, often
this is autoimmune, or genetic or through environmental factors
• Affects 5 – 10 % of diabetics, and onset usually occurs in children or
adolescents

38

Type 2 or non-insulin-dependent diabetes:

Body produces insulin, but receptors are non functional (insulin resistance)
• Affects 90 - 95 % of diabetics, usually in adults over the age of 40, most
often at age 50 to 60
• Can be linked to a number of pathologies, but not sure how or why
• Can be linked to obesity, but not sure how or why.

39

Side effects of diabetes

Excessive thirst (polydipsia)
• Frequent urination (polyuria)
• Extreme hunger or constant eating (polyphagia)
• Unexplained weight loss
• Presence of glucose in the urine (glycosuria)
• Tiredness or fatigue
• Changes in vision
• Numbness or tingling in the extremities (hands, feet)
• Slow-healing wounds or sores
• Abnormally high frequency of infection

40

The lack of functional insulin means that ……………….. so the body asks
for more glucose from both food and body stores. Patient is constantly hungry and eating, why would they lose
weight?

glucose is not able to get inside the cells to make ATP