freshman year study > Bio unit 3 > Flashcards

Bio unit 3 Flashcards

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1
Q

All organisms…..

A

-are made of cells
-acquire and use energy

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2
Q

what is energy

A

the capacity to do work or supply heat
- causing something to move or change — for example, lifting a book, moving a car, or stretching a rubber band all require energy.

Supplying heat means transferring energy from one object to another because of a temperature difference — for example, when the sun warms your skin or a stove heats a pan.

So in short, energy is what makes things happen

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3
Q

2 forms of energy

A

kinetic and potential

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4
Q

Kinetic energy

A

energy of motion — any object that’s moving has kinetic energy.
The faster something moves, or the more massive it is, the more kinetic energy it has.
Example: A moving car or flowing water both have kinetic energy because they’re in motion.

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5
Q

Ea (Activation Energy)

A

type of kinetic energy
-It’s the minimum amount of energy needed for a chemical reaction to start.
-Think of it like the “push” molecules need to collide and react.
Example:
When you light a match, the heat from friction provides the activation energy (Ea) to start the combustion reaction — that’s kinetic energy being used to get molecules moving fast enough to react.

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6
Q

Potential Energy (Ep)

A

stored energy — energy that an object or system has because of its position, condition, or composition.
-It’s energy that has the potential to do work, but isn’t doing work yet.

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7
Q

what is Free energy (G)

A

type of potential energy stored in chemical bonds.
-tells us how much energy is available to do work in a cell or chemical reaction.

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8
Q

2 types of free energy

A

-High free energy (high G) → molecules have a lot of stored chemical energy (like glucose).
-Low free energy (low G) → molecules have less stored energy (like CO₂ and H₂O after glucose breaks down).

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9
Q

1st law of therodynamics

A

energy can not be created nor destroyed just changes form

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10
Q

2nd law of therodyamnics

A

entropy (disorder) is always increasing ( cells use energy to keep things in order)

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11
Q

how many reactions are cells doing

A

1,000’s and 1,000’s

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12
Q

What does it mean that all of a cell’s energy transformations = chemical reactions = metabolism?

A

All the energy changes inside a cell happen through chemical reactions, where bonds are broken or formed and energy is released or absorbed.
The sum of all these reactions (both breaking down and building up molecules) is called metabolism.
➡️ Energy transformations → Chemical reactions → Metabolism

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13
Q

enzymes are what type of macromolecule

A

protien

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14
Q

what is (ΔG)

A

Measures usable energy in a system after accounting for entropy and temperature.
Determines if a reaction releases energy (spontaneous) or requires energy (non-spontaneous).

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15
Q

glysolsis and pyruvate processing steps

A
  • start with glucose (which has 6C)
  • splits into 63P 2 (2 3 carbon molcuels)
  • glusose is split to 2 pyruvate
    -put in nad+ which turns into nadh
    -put in ADP which turns into ATP
    -glucose converted to pyruvate
    -CO2 comes out
    -NADH converts to NADH+
    -convterd to acytla coa
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16
Q

how many steps is glucolsis and what are the names

A

cycle is regenerating

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17
Q

cellialr repsiartuion includes varior — pathways that breakdiwn — and other metablies to priduce—-

A

metablic
glucose
ATP

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18
Q

cellaur repstarion requires—- and gives off —-

A

O2
CO2

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19
Q

areobric respiation usally breaks doewn glucose into — and —-

A

CO2 and H2O

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20
Q

glucose is a high energy recatant and CO2 and H2O are low energy molecules heat/energy is relsed and the reaction must be

A

exergonic

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21
Q

— is oxcdied and O2 is —-

A

glucose
reduced into water

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22
Q

glysolcsis is the brakdown of glucose to form two molecules of —-

A

pyruvate

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23
Q

– ATP molcules are produced in glyclosis

A

2

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24
Q

glycolsis takes place in the —- it does nnot utlize oxygen

A

cytoplams

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25
in the --- pyrvucate is oxcided to an acytel gryo and CO2 is removed
mitocondral matrix
26
the krebs cycle gives off -- and prodcies ---
2CO2 FADH NADH
27
the krebs cycle produces -- moclcles of imediate ATP per glucose
2
28
-ΔG
spontanous relase energy=exergoinic
29
exergonic
release energy Exergonic reactions often release energy because electrons move from a higher-energy state to a lower-energy state. Example: Glucose breakdown (cellular respiration) Glucose’s bonds have high-energy electrons. When glucose is broken down, electrons are transferred to oxygen (forming water). This electron movement releases energy, which the cell captures as ATP.
30
endergoinc
Endergonic reactions often require energy to move electrons “uphill” to a higher-energy state. Example: Photosynthesis Electrons in water are low-energy. Plants use sunlight to excite these electrons to a higher energy level. These high-energy electrons are then used to make glucose.
31
+ΔG
NOT spontanus always need energy input endergoinic
32
ΔG's and reaction type
ΔG < 0 (negative ΔG) → exergonic → reaction releases energy → spontaneous. ΔG > 0 (positive ΔG) → endergonic → reaction requires energy → non-spontaneous. Negative ΔG: rolling downhill → energy comes out Positive ΔG: rolling uphill → energy must go in
33
how do cells use exergoic and endergoic reactions (with the help of ATP)
-Cells need energy to do things like build molecules, pump ions, or move. Those processes are endergonic (need energy). -Cells also break things down, like glucose, which releases energy. Those processes are exergonic (release energy).
34
how do enzymes help reactions
a reaction would stil happen w/out an enzyem but an enzyme helps lower the Ea meaning faster reactions and the delta G does NOT change
35
cofactors
helpers inorganic metal ions zinc & magnssium
36
coenzymes
helpers organic like electron carries FADH2 (cellualr respiration) NADH (cellaurl respiration) NADPH (photosynthesis)
37
Potential energy
-energy that’s stored and ready to be used later. -energy is stored in chemical bonds. -Think of a bond like a compressed spring — it has stored energy. -Breaking or forming bonds can release or store energy.
38
Electrons and covalent bonds
-Electrons are negatively charged particles that “orbit” the nucleus of atoms. -In covalent bonds, electrons are shared between atoms to hold them together. -High-energy electrons (like in glucose) carry energy that can be released when bonds are broken during reactions.
39
Energy transfer = electron movement
-When energy is transferred, it usually happens through moving electrons from one molecule to another. -Example: In cellular respiration, electrons are transferred from glucose to oxygen, releasing energy that’s used to make ATP. -So electrons are basically the carriers of energy inside cells.
40
H+ (protons) attratcion and role
-They are positively charged, so they’re attracted to negatively charged electrons. -In things like the electron transport chain, H⁺ ions are pushed across membranes, creating a proton gradient. -This gradient stores potential energy, like water behind a dam, which can later drive ATP production.
41
oxidation
-loss of electrons -energy: Often releases energy because high-energy electrons are leaving. -Example: Glucose loses electrons when it is broken down to CO₂.
42
Reduction
-Gain of electrons -Energy: Often stores energy because electrons are high-energy particles. -Example: Oxygen gains electrons to form water in cellular respiration.
43
reduction and oxidation example with H+
NAD⁺ + 2e⁻ + H⁺ → NADH (reduction) NADH → NAD⁺ + 2e⁻ + H⁺ (oxidation) So when you see H⁺ or high-energy electrons moving, think redox.
44
photosynthesus light reactions location
thylakoid membrane of chlorplasts photosysytem 2 photosystem 1
45
photosynetheiss light dependt reactions input
photons H20
46
photosynetheiss light dependt reactions output
NADPH ATP O2
47
photosynetheiss light independt reactions input
3CO2 9 ATP 6NADPH
48
photosynetheiss light independt reactions location
stroma
49
photosynetheiss light independt reactions output
suagr
50
What form of energy is Gibbs’ free energy (G)?
Free energy available to do work in a system.
51
What does ∆G represent?
The change in Gibbs’ free energy during a reaction.
52
How do endergonic and exergonic reactions relate to ∆G?
Endergonic: ∆G positive (requires energy). Exergonic: ∆G negative (releases energy).
53
What is a redox reaction?
A reaction where electrons are transferred; oxidation = loss, reduction = gain.
54
What is the overall equation for cellular respiration?
Glucose + Oxygen → Carbon dioxide + Water + Energy (ATP) C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + energy (ATP).
55
Which molecule is oxidized in cellular respiration?
Glucose (C6H12O6).
56
Which molecule is reduced in cellular respiration?
Oxygen (O2).
57
Name the four stages of cellular respiration.
1) Glycolysis, 2) Pyruvate oxidation, 3) Citric acid cycle, 4) Electron transport chain & oxidative phosphorylation.
58
Where does glycolysis occur?
Cytoplasm.
59
What are the two major phases of glycolysis?
1) Energy investment phase, 2) Energy payoff phase.
60
Why is phosphofructokinase important?
It is a key regulatory enzyme and is inhibited by high ATP (feedback inhibition). When ATP levels are high, PFK is turned off, slowing glycolysis. When ATP levels are low, PFK is active, speeding glycolysis up to make more energy.
61
How does substrate-level phosphorylation work?
ATP is produced directly by transferring a phosphate from a substrate to ADP. A “substrate” molecule (something in a metabolic reaction, like in glycolysis or the Krebs cycle) already has a high-energy phosphate group attached. An enzyme helps transfer that phosphate directly from the substrate → to ADP. ADP + P → ATP 💥 (and the substrate loses its phosphate and becomes something else)
62
What happens to pyruvate before entering the citric acid cycle?
Converted to acetyl-CoA, releasing CO2 and producing NADH.
63
How many times does the citric acid cycle turn per glucose molecule?
Two times.
64
What is regenerated at the end of the citric acid cycle?
Oxaloacetate.
65
Where do all carbons from glucose end up?
Released as CO2.
66
What are the net ATP yields of glycolysis, citric acid cycle, and oxidative phosphorylation?
Glycolysis: 2 ATP, Citric acid cycle: 2 ATP, Oxidative phosphorylation: ~32 ATP.
67
Where is the electron transport chain located?
Inner mitochondrial membrane.
68
What is the role of NADH and FADH2 in the ETC?
Donate electrons to the chain to generate a proton gradient.
69
What is the final electron acceptor in aerobic respiration?
Oxygen, which is reduced to water.
70
What is oxidative phosphorylation?
ATP production using the proton gradient and ATP synthase.
71
What is Q (ubiquinone) in the ETC?
Electron carrier transferring electrons between complexes.
72
What is a photoautotroph?
Organism that uses light energy to make organic molecules (e.g., plants, algae, cyanobacteria).
73
Where do the light reactions of photosynthesis occur?
Thylakoid membranes of the chloroplast.
74
What wavelengths of visible light are used in photosynthesis?
400–700 nm. Short wavelengths = more energy (like blue/violet light) Long wavelengths = less energy (like red/orange light)
75
Why are accessory pigments important?
Expand the range of light that can be absorbed for photosynthesis.
76
What are the products of the light-capturing reactions?
ATP, NADPH, and O2.
77
What is photophosphorylation?
Production of ATP using light energy during the light reactions.
78
What happens in Photosystem II?
Water is split, producing electrons, protons, and O2; electrons are excited and passed to the ETC.
79
What happens in Photosystem I?
Electrons are re-excited and used to reduce NADP+ to NADPH.
80
How many carbons does pyruvate have when converted to acetyl-CoA?
3 carbons → 2 carbons in acetyl-CoA + 1 carbon released as CO2.
81
How many times does pyruvate oxidation occur per glucose molecule?
Twice (once for each pyruvate).
82
What is the main purpose of the citric acid cycle?
To extract high-energy electrons for the ETC and produce ATP, NADH, and FADH2.
83
How many NADH and FADH2 are produced per citric acid cycle turn?
3 NADH and 1 FADH2 per turn.
84
How many CO2 molecules are released per citric acid cycle turn?
2 CO2.
85
How does feedback inhibition regulate the citric acid cycle?
High levels of ATP or NADH inhibit key enzymes, slowing the cycle.
86
What is PQ (plastoquinone) in photosynthesis?
Electron carrier transferring electrons from PSII ps1.
87
What is PC (plastocyanin)?
A protein that transfers electrons from the cytochrome complex to PSI.
88
Why do we need both PSI and PSII?
PSII provides electrons from water; PSI provides high-energy electrons to make NADPH.
89
main thinsg to know about glycolsis
-occurs in cytoplasm - main input: 1 glucose -main outputs: 2 pyruvates energy output per glucose: 2 atp, 2 nadh
90
main things to know about pyruvate oxdiation
occurs in: pyruvate us transposted into the mitocondra - main input: 2 pyruvates, 2 coenzyme A - main output: 2 acytel COA's - main energy output: 2 NADH
91
main things to know about citric acid cycle
-occurs in: matrix of mitochondia - main input: 2 actyel Co-A oxalocetate - main output: oxalocetate -energy outputs: 6 NADH, 2 FADH2, 2 ATP
92
(ETC) main things to know about oxidative phosphorylation
-occurs in: inner matochondral membrane - main input: 10 NADH, 2 FADH2, 2 O2 - main output: water, 10NAD+, 2 FAD+ - energy outputs: 30 ATP
93
Chlorophyll a & b – What are they, what colors do they absorb and reflect, and what is their role in photosynthesis?
Definition: Pigments in plants that capture light energy for photosynthesis. Chlorophyll a: Main pigment Absorbs: blue (~430–450 nm) and red (~662 nm) Reflects: green → why plants appear green Role: Directly participates in the light reactions by transferring excited electrons Chlorophyll b: Accessory pigment Absorbs: blue (~455 nm) and orange (~640 nm) Reflects: green-yellow Role: Passes absorbed energy to chlorophyll a, helping capture more light Key Point: Together, they maximize light absorption for photosynthesis while reflecting green light.
94
Cellular respiration is blank and blank
Catabolic: breaks down bigger molecules into smaller ones, releasing energy Since cellular respiration breaks glucose down into CO₂ and H₂O, it is catabloic Exergonic: releases energy (ΔG < 0) Cellular respiration releases energy stored in glucose → ATP is made, so it is exergoinc
95
FAD is the balnk form of one of the electron carriers (electron shuttles) in cellular respiration.
oxidized form FADH₂ = reduced form (carries electrons and hydrogen) FAD = oxidized form (ready to accept electrons)
96
anabloic vs catoblic
catbloic is small to large anabloic is large to small
97
What are carotenoids?
Carotenoids are pigments found in plants, algae, and some bacteria. They are the orange, yellow, and red colored molecules that help plants absorb light for photosynthesis and also protect them from damage by too much sunlight.
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