Exam 2 (6-8) Flashcards
1
Q
energy
A
ability to do work (movement of matter)
2
Q
potential energy
A
stored energy available to do work (chemical energy, ATP)
3
Q
kinetic energy
A
energy being used to do work, energy of movement (whale surfacing ocean)
4
Q
how efficient are cells at converting potential energy to kinetic energy?
A
cells are only 40% efficient at generating energy, 60% remaining comes in product of heat
5
Q
heat
A
random motion of molecules
6
Q
thermodynamic law of conservation of energy
A
energy cannot be created or destroyed, rather it changes form
7
Q
thermodynamic law of entropy
A
energy cannot change from one form to another without the loss of usable energy
8
Q
entropy
A
heat energy is disordered, all energy transformations will increase disorder, and therefore energy
Ex: cellular respiration - glucose + O2 converts to CO2 + H2O + ATP
generates energy, and ATP has a lot of potential energy, making it less stable
8
Q
examples of potential energy
A
ATP, starting a car, water about to fall over a dam, concentration gradients
8
Q
metabolism
A
all the chemical reactions in a cell. energy converting forms
9
Q
endergonic reactions
A
reactions have less energy than the products +delta G and the reaction requires the input of energy
9
Q
examples of kinetic energy
A
anything with movement, water falling over dam, car driving
10
Q
exergonic reactions
A
reactants have more energy than the products -delta G and the reaction will occur spontaneously (no energy input needed)
10
Q
examples of endergonic reactions
A
photosynthesis, the formation of ATP
11
Q
examples of exergonic reactions
A
cellular respiration, break down of ATP into ADP
12
Q
ATP functions
A
- chemical work - synthesizing macromolecules
- mechanical work - contraction of muscles
- transport work - moving things across concentration gradient
13
Q
coupled chemical reactions
A
both energy favorable and unfavorable reactions occur in same place at the same time
Ex: ATP hydrolysis and ATP synthesis
14
Q
calorie
A
unit to measure energy, the energy required to raise the temperature of 1g of a substance by 1 degree C
15
Q
kCal
A
1000 calories, a single calorie in food is refers to a single kCal
16
Q
enzymes
A
molecules that catalyze chemical reactions without being consumed, reduce energy activation, end in -“ase”
17
Q
metabolic pathways
A
a series of linked reactions that are each catalyzed by an enzyme, need the previous enzyme and substates product to create next reaction
18
Q
degradation reaction
A
substrate is broken down into smaller products
19
Q
synthesis reaction
A
substrates are combined to create a larger product
20
Q
enzyme denaturation
A
factors that change shape of an active site preventing efficient binding of substrate
21
factors that affect enzyme activity
pH, temperature, concentration of substrate, regulating molecules (competitive and noncompetitive inhibitors, cofactors)
22
concentration of a substrate
need for a certain number of substrates to allow for adequate enzyme function
23
temperature for enzymes
impacts speed of enzyme, an optimal temperature is the point where an enzyme functions best, and a range around this optimal point also allows the enzyme to function, depends on type of enzyme
24
regulation - promoting enzymes
cofactors and coenzymes - increase enzyme activity
25
cofactors
inorganic, bind to an enzyme, examples include FAD, NADP+, and NAD+
26
coenzymes
organic, non protein molecules
27
regulation - inhibiting enzymes
competitive inhibitors and allosteric inhibitors - decreases / limits enzyme activity
28
allosteric inhibitors
non active site inhibition, prevent enzyme function, such as binding to allosteric site and changing shape of active site
29
competitive inhibitors
bind to active site to prevent enzyme function
30
noncompetitive inhibition
negative feedback loop that prevents wasteful production of products due to activity through regulating enzyme activity
31
REDOX reactions
oxidation and reduction reactions that are facilitated by specific enzymes to move electrons. essential for photosynthesis and cellular respiration!
32
oxidation
OIL - oxidize is lost - the loss of electrons / hydrogen ions
33
reduction
RIG - reduce is gain - the gain of electrons / hydrogen ions
34
redox in photosynthesis / photosynthesis equation
6 CO2 + 6 H2O --> C6H12O6 + 6 O2
--> Reduction occurs from 6 CO2 to C6H12O6 (H+ are gained)
--> Oxidation occurs from 6 H2O to 6 O2 (H+ are lost)
35
redox in cellular respiration / cellular respiration equation
C6H12O6 + 6 O2 --> 6 CO2 + 6 H2O + ATP
--> Oxidation occurs from C6H12O6 to 6 CO2 (H+ are lost)
--> Reduction occurs from 6 O2 to 6 H2O (H+ are gained)
36
helper molecules
the molecules necessary for the oxidation of glucose. include enzymes and coenzymes
37
aerobic CR
final electron acceptor is Oxygen
38
anaerobic CR
final electron acceptor is NOT Oxygen
39
molecules involved in CR
- ATP
- Pyruvate (3 carbon molecule)
- Acetyl CoA (2 carbon coenzyme)
- NAD+ / NADH (electron carrier molecule)
- FADH / FADH+ (electron carrier molecule)
40
order of CR processes
glycolysis, (preparatory step), krebs cycle, oxidative phosphorylation
41
glycolysis
- first phase of CR
- occurs in cytoplasm
- involves converting glucose (a 6 carbon) into pyruvate (3 carbon)
- leads to a gain of 2 ATP
- is an anaerobic process, and therefore primative
42
glycolysis inputs and outputs
Inputs
6C glucose
2 NAD+
2 ATP
4 ADP + 4 P
Outputs
2 (3C) Pyruvate
2 NADH
2 ADP
4 ATP
Net gain: 2 ATP
43
energy investment of glycolysis
2 ATP are used to activate glucose, adding their P's to break glucose down into 2 G3P
44
energy harvesting of glycolysis
- oxidation of G3P occurs, through removing H+ ions and electrons (substrate level ATP synthesis occurs)
- oxidation of BPG occurs via dehydration synthesis (substrate level ATP synthesis occurs)
- 2 molecules of pyruvate result, as well as 2 NADH and 2 ATP
45
substrate level ATP synthesis
when enzymes are involved in the production of ATP, occurring OUTSIDE mitochondria during glycolysis, in the cytoplasm
46
oxidative phosphorylation
occurs INSIDE the mitochondria, during ETC / chemiosmosis
47
fermentation
anaerobic process producing a limited amount of ATP when oxygen is not available
- varies by enzyme
- produces by-products of lactate (animals) or alcohol (plants)
48
fermentation inputs and outputs
inputs
- glucose
- 2 ADP + 2P
outputs
- 2 lactate or 2 alcohol & 2 CO2
Net gain: 2 ATP
49
where is atp generated and how many in each step?
glycolysis (cytoplasm)
2 ATP
krebs cycle (mitochondria, matrix)
2 ATP
ETC / chemiosmosis (mitochondria, inner membrane)
32 ATP
50
cristae
mitochondria, short fingerlike projections formed by the folding of the inner membrane, where the ETC phase takes place, increase surface area
51
matrix
mitochondria, semi-fluid substance inside organelles and the mitochondria where prep reaction and krebs cycle occurs
52
preparatory step inputs and outputs
C3 Pyruvate is converted into acetyl CoA molecules
Inputs
- 2 pyruvate
- 2 CoA
Outputs
- 2 acetyl CoA
- 2 CO2
53
kreb's cycle
- aka citric acid cycle
- 3rd phase of CR (or second without prep step)
- must run X2!!
- occurs in the matrix of the mitochondria
- leads to a net gain of 2 ATP
- NAD+ reduced to NADH (3x per cycle, 6 total)
- FADH reduced to FADH2 (1x per cycle, 2 total)
- carbon molecules from glucose converted into CO2
54
pyruvate
3 carbon molecule
55
acetyl CoA
2 carbon molecule attached to coenzyme A (CoA)
56
NAD+/NADH
electron carrier molecule
57
FADH/FADH2
electron carrier molecule
58
kreb's cycle inputs and outputs
inputs
- 2 (2C) acetyl groups
- 6 NAD+
- 2 FAD
- 2 ADP + 2 P
outputs
- 4 CO2
- 6 NADH
- 2 FADH2
net gain: 2 ATP
59
Electron transport chain (ETC)
- final phase of CR
- takes place inside mitochondria in inner membrane
- movement across a concentration gradient DOWN the gradient, high to low energy CHEMIOSMOSIS
- involves electron donors FADH2 and NADH
- electron acceptor THE FINAL ONE is oxygen
60
Chemiosmosis
mitochondria uses energy of ETC to create a hydrogen ion gradient that drives ATP production
61
role of ATP synthase
A complex in the inner membrane that forms ATP through chemiosmosis
- uses concentration gradient to gather energy from H+ to bond ADP with a phosphate
- for every three protons added, enough energy is generated to bind a P to ADP to form ATP
62
role of ETC in oxidative phosphorylation
ETC allows electron donors (FADH2 & NADH) to release electrons at beginning of chain (oxidation) where they are the energy to move Hydrogen ions out of the membrane, creating a higher concentration of H+ outside the membrane than inside the membrane. This allows the concentration gradient to be harnessed for energy in the ATP synthase complex that produces ATP.
*oxygen is the final electron acceptor and takes 2 hydrogen ions to form water
63
ETC inputs and outputs
prior to ETC (inputs)
- 4 ATP
- 6 NADH+
- 2 FADH2
outputs
- 32 ATP
*realistically is around 30 because of energy needed for movement
64
ETC members
Complexes / Protein pumps
- NADH-Q reductase
- cytochrome reductase
- cytochrome oxidase
Carriers / Transporters
- coenzyme Q
- cytochrome C
65
role of proton pumps
- Move protons OUT of matrix and into the intermembrane space
- protons will then move back into the matrix to balance gradient, and allow for ATP synthase to create ATP
66
Overall yield of ATP in CR
theoretical yield is 36-38 ATP
actual yield is 30 ATP, because only 32-39% of energy from glucose = ATP
energy is used to...
- move NADH into cell
- move pyruvate and ADP into cell
67
catabolism
breakdown of molecules, degrative reactions
68
anabolism
synthesis of molecules, constructive reactions
69
metabolic pool
balance between catabolic and anabolic reactions, and the overall balance of metabolism
70
autotroph
organisms that produce their own food
- need inorganic nutrients
- energy source outside organism
71
heterotroph
organisms that require pre-formed organic nutrients to be used as an energy source
72
marine photosynthetic autotrophs
phytoplankton, sea grasses, seaweeds (sargasso / sargassm), cyanobacteria
73
what are the organisms that break down nitrogen gas?
diazotrophs
74
photosynthesis
the process by which plants, algae and some prokaryotes harness solar energy and convert it into chemical energy
75
stoma
cells on the exterior of cell layers in plant, found in leaves
76
stomata
plural of stoma, where gas is diffused through the leaf
77
# what components are in the...
chloroplast
organelle of photosynthesis, green, have granums that contain thylakoids, inner and outer membranes, and DNA rings
78
etymology of chloroplast
"chloro" - green
"plast" - formed / molding
79
chlorophyll
one of the primary pigments of photosynthesis, housed in the photosystem, also abbreviated as chl
80
photosystems
large embedded reaction center holding clusters of pigments and proteins participating in photosynthesis, found in thylakoid membrane
81
electromagnetic spectrum
range of radiation
82
photon
discrete packet of kinetic energy, come in form of solar energy / UV light
83
wavelength
distance of movement during complete vibration in nanometers (nm), have an inverse relationship with energy
84
as energy increases
wavelength decreases
85
as wavelength increases
energy decreases
86
absorption spectrum
different wavelengths absorb different amounts of energy, absorbing different parts of the visible spectrum
87
what do cholorphyll absorb?
purples and blue (380 - 500 nm), and orange and red (600 - 750 nm)
88
what does chlorophyll reflect?
yellow and green
89
photosynthetically active radiation (PAR)
measurement of wavelength of light (nm) on relative absorption (%), shown in a graph of various pigments...
90
how is UV light different in the water?
UV wavelengths are different because they are based on depth of absorption. Blue wavelength goes deepest, which is why the ocean appears blue
91
light reactions inputs and outputs
inputs:
- water
- UV light
- ADP
- phosphate
outputs:
- oxygen
- NADPH
- ATP
92
Calvin cycle inputs and outputs
inputs:
- NADPH
- ATP
- CO2
outputs:
- CH2O (simplified glucose).. leads to glucose
93
light reactions
- conversion of solar energy into chemical energy
- occurs in thylakoid membrane
- goal is to get energy from electrons
- H2O input
- O2 output
94
carbon / calvin cycle reactions
- produce sugar molecules from energy
- occurs in the stroma
- CO2 input, glucose output
95
photosystem II
electrons are transferred here, where breakdown of water occurs via photolysis, electrons are then transferred down ETC in the thylakoid membrane
96
photolysis
breaking water down into hydrogen and oxygen
97
photosystem I
where NADP+ is reduced to create NADPH, this is then used combined with ATP in the calvin cycle, this also causes movement of H+ out of stroma and into thylakoid space
98
what does the ETC do in photosynthesis?
pumps H+ ions into the thylakoid space, creating a concentration gradient. This energy is then used during the production of ATP via ATP synthase as the movement BACK INTO the stroma produces energy to bind P + ADP to make ATP
99
cyclic pathway in photosynthesis
electrons cycle through pathway in photosystem I
100
noncyclic pathway in photosynthesis
photosystem II electron transfer to ETC
photosys II in general...
101
calvin cycle reactions
carbon fixation, CO2 reduction, RuBP regeneration
102
carbon fixation
- CO2 is attached to RuBP
- creates unstable 6C molecule that splits into 3C molecules
103
CO2 reduction
3PG is reduced to G3P:
1) ATP --> BPG (3 carbon)
2) NADPH --> G3P (3 carbon)
104
RuBP regeneration
takes 3 turns of calvin cycle to regenerate 1 G3P for glucose
- remaining 5 G3P molecules are used to reform 3 RuBPs
105
What is G3P used for?
amino acids, fatty acids, and glucose phosphate, which can be turned into fructose phosphate and then sucrose, or starch and cellulose.
106
When does RuBP bind to CO2?
LOW temp, high CO2 to O2 ratio, known as the calvin cycle
107
when does RuBP bind to O2?
HIGH temp, high O2 to CO2 ratio, known as photorespiration
108
C3 carbon fixation pathways
- temperate conditions
- mesophyll
- ex: wildflowers
109
C4 spatial separation
- hot and dry conditions
- starts in mesophyll cell but carbon fixation occurs in BUNDLE SHEATH CELL
- PEP Carboxylase - moves CO2 to specialized bundle sheath cells (acts as a transporter)
110
CAM plants temporal separation
- change TIME when carbon is fixed and when Calvin cycle run
- ex: pineapple
- typically occurs in a warmer env
- PEP case converts to CO2 to C4
111
carbon fixation pathways... what's their purpose?
- avoids wasting energy through photorespiration that would occur without adaptations
- hot climates -- stomata close needing adjustment to allow Calvin cycle to occur
112
what can carbon signatures indicate?
the different carbon isotopes are what is used to carbon date -- the change in a carbon fixation pathway can be used to determine what plants are involved in whatever is being studied
