Bioenergetics Flashcards

1
Q

define bioenergetics? draw a molecule of ATP?

A

the study of energy relationships & energy transformations in biological systems.

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2
Q

Potential energy is stored in ________________ and is released as kinetic energy when these bonds __________.
The ability of ATP to store and release energy is due to ____________.
where is ATP mostly made?

A

chemical bonds
break
its molecular structure.
mitochondria

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3
Q

when a molecule loses a hydrogen atom, it _____________
when a molecule gains hydrogen atom, it ________________.
________ in ATP is a high-energy bond.
ATP is often called as ________________.

A

actually loses an electron (oxidation)
actually gains an electron (reduction)
The covalent bond connecting 2 phosphates
energy currency

cz a hydrogen atom contains 1 proton & 1 electron.

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4
Q

what is the nucleoside component called? what does it contain? what is nucleoside?

in ATP

A

ATP consists of a nucleoside component (adenosine)
Adenosine: The nucleoside portion includes the nitrogenous base adenine and the five-carbon sugar ribose.
- A nucleoside is similar to a nucleotide but lacks the phosphate group.
- It consists of a nitrogenous base and a five-carbon sugar.

3 phosphate groups are attached to adenosine.

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5
Q

Each ATP molecule consists of ?
what is ATP used for? _______ is produced as a by-product in photosynthesis.

A

(a) adenine - a double-ringed nitrogenous base

(b) a ribose - a five-carbon sugar.

(c) three phosphate groups (PO4) in a linear chain called triphosphate group.
oxygen

synthesis of macromolecules, movement, transmission of nerve impulses, active transport, exocytosis & endocytosis etc.

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6
Q

The breaking of ______________ releases about 7.3 kcal (7,300 calories) per mole of ATP. what is this called?

write formula for it.

A

one phosphate bond
ATP + H2O → ADP + Pi + energy (7.3 kcal/mole)
hydrolysis reaction

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7
Q

ATP is _________ by which processes?
and is _____________ by which processes?
why ATP need to be broken down?

A

generated
energy-releasing
broken down
energy-consuming
for energy
when cells breakdown molecules, the energy released is stored in ATP (ATP is made from ADP) (P.E), when energy is needed, ATP breaks down which releases energy.

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8
Q

Photosynthesis is __________process.
how do plants intake CO2?
state the formula?
where does water come from?
how does water enter?

A

anabolic (building)
CO2 diffuses from the external environment through the stomata into the air spaces of the leaf.
Thin layer of H2O surrounds the surface of mesophyll cells. CO2 dissolves in this water & diffuses into mesophyll cells.
from soil
Water is present in soil it is absorbed by root hair cells by osmosis. It then transportes to the leaves by xylem tube.

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9
Q

what is the importance of redox reactions?

A

play a key role in energy flow through biological systems cz electrons that pass from 1 atom to another carry P.E
the electron tranfers aka redox reactions are essential part of cellular respiration & photosynthesis

thus redox reactions play a key role in the flow of energy

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10
Q

what are pigments?
which wavelengths are absorbed? and where
why does a leaf look green.
how photosynthesis utilizes light?
how visible light come in?

A
  1. light absorbing molecules
  2. blue, red & orange in membranes of thylakoids
  3. cz it reflects mainly green light
  4. photosynthesis utilizes only small portion of EM spectrum known as visible light which comes in discrete packets called photons.
  5. comes in discrete packets called photons.

pigments are there in cholorplasts which contain thylakoids.

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11
Q

where is chlorophyll present?
define photosynthetic pigments.
________ is the site of photosynthesis.
define photosystems? where is it located?
why is chlorophyll a necessary for photsynthesis?
______ is the green pigment?
chloroplast or chlorophyll?

A
  1. membranes of thylakoids (in chloroplast)
  2. molecules that facilitate converting light into C.E in plants & other photosynthetic organisms.
  3. chloroplast
  4. clusters of photosynthetic pigments in thylakoid membranes.
  5. it converts light energy into C.E.
  6. chlorophyll

if chlorophyll is present in membranes of thylakoids then photosystems will also be located there.
Chloroplast = organelle

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12
Q

Photosynthesis occurs in ______ phases.
what happens in first phase? where?
what happens in 2nd phase? where?

A
  1. two light dependent reactions light independent reactions
  2. light energy is captured and is used to make high-energy molecules.
    These reactions are known as light reactions, take place on the thylakoid membranes of chloroplasts.
  3. CO2 is reduced by NADPH to make glucose. In this phase, the energy from high energy molecules is utilized. Since these reactions do not use light directly, they are dark reactions.
    The dark reactions take place in the stroma of the chloroplasts.

dark reactions = light independent reactions

high-energy molecules (ATP and NADPH).

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13
Q

what happens in light reactions?
why electron is given to chlorophyll?
why light acts on photosystem I?
where does NADPH come from?

A
  • When chlorophyll molecules absorb light, their energy level increases and their electron pair is emitted.
  • emitted electron are passed to electron transport chain to produce ATP.
  • Light also breaks H2O molecule (photolysis) and O is released. The H atoms of H2O give electrons to chlorophyll and become ions.
  • The electrons of chlorophyll, after the production of, and the H ions of H2O are used for the reduction of NADP+ into NADPH.
    to compensate its electron loss.
    to give out an electron pair. These electrons & 2 H+ of H2O reduce NADP+ to NADPH.
    electrons that reduce NADP+ to NADPH.

chlorophyll is a pigment that absorbs red orange blue

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14
Q

what happens in Calvin cycle?
where does 5-carbon molecule come from?
chemical formula for?
1. 5-carbon molecule
2. 3-carbon molecule
3. 3-carbon sugar molecule.

WHAT is RuBP?
what & how is reduced to 3 carbon sugar molecule?

A
  • CO2 molecules are combined with 5-carbon molecule to form 2 temporary 6-carbon molecules, each of which splits into two 3- carbon molecule.
  • The 3-carbon molecule are reduced to 3-carbon suag by using ATP and hydrogen from NADPH. The 3-carbon sugar are used to manufacture glucose.
  • The 3-carbon sugar are also used to regenerate the original 5-carbon molecule. This step also utilizes ATP.

they already exist (from 3 carbon sugar)
RuBP
3PGA
G3P
a 5-carbon molecule that acts as a CO2 acceptor in the Calvin cycle in photosynthesis.
3 carbon molecule by NADPH by using ATP

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15
Q

how is 3PGA formed?
where does Calvin cycle start from? where does it take place?
draw overview of photosynthesis.

3PGA = Please Golf Afternoon

A

6 carbon molecule splits into two 3 cabron molecules (3PGA)
5 carbon molcule + CO2= 6 carbon molecule
stroma of chloroplast.

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16
Q

what is limiting factor?
name them?

A

any environmental factor that tends to restrict the process of photosynthesis.
light intensity
CO2 concentration
temperature
an increase in light intensity speeds up photosynthesis, but only up to a point. Beyond this point any further increase in light intensity has no effect on rate of photosynthesis. Becuase all available chlorophyll molecules are fully occupied in light absorption.

at much higher light intensity, the rate of photosynthesis becomes constant.

17
Q

why increase in CO2 concentration can decrease the rate photosynthesis?
optimum temp. for plants?
why suitable temp. is imp. for plants?
which is a by-product in photosynthesis?

A
  • Increase in CO2 concentration beyond a certain level causes the closure of stomata and it decreases the rate of photosynthesis.
  • 25° C
  • for photosynthesis to take place at normal rate.
  • oxygen gas

CO2 concentration rises, the rate of photosynthesis goes on increasing.

18
Q

what is respiration? where is it done? types?

A

metabolic process by which energy is produced from food.
in cells
2 aerobic anaerobic

19
Q

define glycolysis? where does it take place? why glycolysis occurs in aerobic and anaerobic? formula?

A

the first step that extract energy from glucose by splitting it into 2 three-carbon molecules called pyruvates.
in cytoplasm (aerobic & anaerobic)
oxygen is not involved
a single molecule of glucose is broken down into 2 molecules of pyruvic acid having 3 carbons. Two ATP molecules are produced as net energy gain. Two NAD+ molecules are reduced to NADH.
Glucose → 2 Pyruvate + 2 ATP + 2 NADH

20
Q

what is alcoholic fermentation? where does it happen?
chemical formula of alcohol & lactic acid?
what is lactic acid fermentation? where does it happen?

A

In this type of anaerobic respiration, pyruvic acid is converted into alcohol & CO2. It occurs in bacteria, yeast etc.
(C2H5 OH) (C2H6O3 )
Pyruvic acid→ 2 Ethanol + 2 CO2 + Energy (ATP)
In this type of anaerobic respiration, each pyruvic acid molecule is converted into lactic acid.
It occurs in skeletal muscles of humans during extreme physical activities.
This also happens in bacteria present in milk.

Pyruvic acid → Lactic Acid

21
Q

importance of anaerobic respiration?
the soy sauce is made through the fermentation by a ____________.

A
  1. The very first organism had to produce energy by anaerobic respiration because the early Earth had no free oxygen in its atmosphere.
  2. anaerobic respiration by bacteria is used in cheese & yogurt making.
  3. fermentation by yeast is used in wine making & baking.
  4. anaerobic respiration provides energy to muscle cells during running or strenuous exercise by using lactic acid fermentation.
    fungus Aspergillus
22
Q

how acetyl CoA is formed? where will it go?
formula of the process?

A

each pyruvic acid molecule oxidizes to a 2-carbon acetyl group which combines with coenzyme A to form acetyl CoA.
to mitochondrion where Krebs cycle will occur.

CO2 & NADH & FADH2 is released too.

pyruvic acid is changed into a 2-carbon compound called acetyl-CoA.

23
Q

Acetyl CoA → ?
name this? where does it happen?
full form of ETC?
where is ETC present?

A

4CO2 + 2ATP + 6NADH + 2FADH2.
Krebs cycle
mitochondrial matrix
electron transport chain
inner membrane of mitochondria.

24
Q

how much ATP molecules aerobic respiration produces?
what is ETC? location?
where do electron passing through ETC come from?
each FADH2 produces ______ ATP molecules.
where do electrons go at last?

A

38 ATP molecule per molecule of glucose 2 ATPs are utilized so net energy gain = 36 ATPs.
series of electron carriers
in glycolysis e- removed by oxidation of glucose & Krebs cycle (NADH) carried by NADH & FADH2.
2
electron combines with molecular oxygen & then that oxygen combines with hydrgen ions to produce H2O.

electrons move through the series of electron carriers they lose energy, which is used to synthesize ATP

25
Q

what is NADH?
why is CO2 & H2O required in photosynthesis?

A

coenzyme carrying high energy electrons

CO2 provides C & O for the synthesis of glucose molecule. (C6 H12 O6)

H2O provides H which is used to reduce (gain H atom) CO2 to glucose.

coenzyme= large organic molecule

26
Q

comparison of respiration & photosynthesis?

A

pg 103

27
Q

comparison of aerobic & anaerobic respiration?

A

pg 103