Gibson Exam 3
Terms in this set (106)
What do living cells require?
Energy from outside sources
What do living cells obtain energy by?
Eating plants or feeding on organisms that eat plants
Cells use chemical energy stored in what?
organic molecules to regenerate ATP
Why do cells need energy?
polymers of the cytoskeleton, movement of vesicles or muscles
What is the breakdown of organic molecules?
What does aerobic respiration consume?
Organic molecules and O2 and yields ATP
Harvesting of energy from glucose has three stages. What are they?
glycolysis, krebs cycle, oxidative phosphorylation
What does all three of these stages produce?
Which stage produces the most ATP?
What stages produce ATP by substrate level phosphorylation?
Glycolysis and krebs cycle
How does glycolysis breakdown?
glucose into two molecules of pyruvate
Where does glycolysis occur in?
Glycolysis has two phases and 10 steps...they are?
energy investing phase
energy producing phase (steps 6-10)
What does each step have in common?
each step has an enzyme
Does glycolysis occur in the absence of oxygen?
yes. glycolysis occurs whether or not oxygen is present
What is step 1 in glycolysis?
-converts: glucose to glycose 6-phosphate
What is step 3 (commitment step) in glycolysis?
-converts: fructose 6-phosphate to fructose 1,6-bisphosphate
-enzyme: phosphofructokinase (regulated by PEP and ADP)
What is step 10 in glycolysis?
-converts: phosphoenol-pyruvate (PEP) to pyruvate
-enzyme: pyruvate kinase
-generates what: 2 molecules of ATP
What are the products pf glycolysis?
ATP, NADH, H2O, pyruvate
Where are the products of glycolysis used?
How does pyruvate enter the mitochondria from the cytosol?
Through a protein. Pyruvate is charged and needs a protein in order to cross the plasma membrane
What must be present in order for pyruvate to enter the mitochondria?
Before the krebs cycle, what must happen to pyruvate?
It must be converted into acetyl CoA
The krebs cycle has how many steps?
8 each has an enzyme
What happens in step 1 (krebs cycle)?
-Acetyl CoA adds its two carbon group to oxaloacetate, producing citrate
What happened in steps 2-7?
Citrate is decomposed back to oxaloacetate
Products of the krebs cycle?=
ATP, CoA, FADH2, NADH, CO2
Where does Krebs cycle happen?
NADH and FADH2 are electron carries and they donate their electrons to the electron transport chain
After glycolysis and the krebs cycle, what accounts for most of the energy that is extracted from food?
Where is the electron transport chain located (Oxidative phosphorylation)?
inn the inner membrane (cristae) of the mitochondria
How do electrons flow through the electron transport chain?
1a) Electrons are transferred from NADH to complex I
1b) Electrons are transferred from FADH2 to complex II
2) Both complex I and complex II transfer their electrons to Q
3) Q transfers the electrons to complex III
4) Complex III transfers electrons to Cyt C
5) Cyt c transfers electrons to complex IV
6) Complex IV transfers electrons to oxygen
What is the final electron accepter?
what produces in the matrix?
Does the electron transport chain generate ATP?
No the electron transport chain +ATP synthase does
What does the electron transport chain generate?
The H+ gradient is referred to as...
a proton motive force
The H+ gradient drives
H+ moves back across the membrane, passing through what?
The protein complex ATP synthase
the use of the energy in a H+ gradient to drive cellular work
Most celular respiration requires oxygen to produce ATP, what will happen is oxygen is not present?
The electron transport chain will cease to operate
When this happens (without oxygen)...
glycolysis couples with fermentation or anaerobic respiration to produce ATP
uses an electron transport chain with a final electron acceptor other than oxygen
Uses substrate level phosphorylation instead of an electron transport chain to generate ATP
What are the two types of fermentation?
Alcohol and lactic acid
-Pyruvate is converted to ethanol in two steps
-First step releases CO2 from pyruvate, and the second step reduces acetaldehyde to ethanol
Lactic acid fermentation
-Pyruvate is reduced by NADH, forming lactate as an end product, with no release of CO2
-Human muscle cells use lactic acid fermentation to generate ATP when O2 is scarce
Versatility of Catabolism
Catabolic pathways funnel electrons from many organic molecules into cellular respiration
Can glycolysis accept a wide range of carbohydrates?
The process that converts solar energy into chemical energy
-Sustain themselves without eating anything derived from other organism
-They are the producers. Produce organic molecules from CO2 and other inorganic molecules
Almost all plants
Use the energy of sunlight to make organic molecules
What does photosynthesis convert to?
Light energy to the chemical energy of food
What is the location of photosynthesis?
Where do leaves get their green color?
From chlorophyll, the green pigments within chloroplasts
Chloroplasts are found mainly in cells of
-Mesophyll (the interior tissue of the leaf)
-Each mesophyll cell contains 30-40 chloroplasts
Light is a form of what kind of energy...
Light travels in...
distance between crests of waves
the entire rang of electromagnetic energy or radiation
consists of wavelength that produce colors we can see
What are pigments?
Substances that absorb visible light
Do all pigments absorb the same wavelength?
Different pigments absorb different wavelength
Wavelengths that are no absorbed are...
Reflected or transmitted
the main photosynthetic pigment
Broadens the spectrum used for photosynthesis
absorb excessive light that elude damage chlorophyll
What does a spectrophotometer measure?
-A pigment's ability to absorb various wavelengths
-Machine sends light through pigments and measures the fraction of light transmitted at each wavelength
What is an absorption spectrum
It is a graph plotting a pigment's light absorption versus wavelength
What does the absorption of chlorophyll a suggest...
That violet-blue and red light work best for photosynthesis
What does the action spectrum profile...
The relative effectiveness of different wavelengths of radiation in driving a process
Name and describe the two ways in which ATP is made during cellular respiration. During what stages in the process does each type occur?
-Substrate level (Gylycolysis and Krebs cycle)
What processes in your cells produce the CO2 that you exhale?
Krebs cycle and connection point
What is the final electron acceptor during cellular respiration?
If complex IV were nonfunctional could chemiosmosis produce any ATP and if so how would the rate of synthesis be different?
If you do not have complex IV you will lose one protein complex that translocates the hydrogen's to create the proton motor force. The rate of synthesis would tapper off and then stop
A glucose fed yeast cell is moved from an aerobic environment to an anaerobic one. How would its rate of glucose consumption change if ATP were to be generated at the same rate?
Rate of glucose would have to increase incredibly
What is the distinction between autotrophs and heterotrophs?
-Autotrophs sustain themselves without eating anything derived from other organisms
-Heterotrophs obtain their organic material from other organisms
What color of light is least effective in driving photosynthesis? Explain your reasoning
Green light is least effective because there are no pigments that absorb the green light energy (see absorption spectrum)
The light dependent reaction of photosynthesis supply the Calvin cycle with what reactant?
ATP and NADPH
If the dark reaction of photosynthesis is inhibited will the process of photosynthesis produce ATP?
Yes. The light dependent reaction produced ATP
In an experiment, isolated chloroplasts placed in an illuminated solution with the appropriate chemicals can carry out ATP synthesis. Predict what will happen to the rate of synthesis if a compound is added to the solution that makes membranes freely permeable to hydrogen ions?
Rate of synthesis will stop. You will no longer have the proton motor force
What is the final product in Photosystem I?
Oxygen, ATP, NADPH, H+
What are the products for Oxidation Phosphorylation?
ATP, NAD+, FAD, H2O
What colors does chlorophyll a and b work best under?
Violet blue and Red
What are the two stages of photosynthesis?
Light reactions and Calvin cycle
light capturing in the thylakoid membrane of the chloroplast or in the membrane of some prokaryotes
reaction center complex
molecules absorbing energy, one of the electrons is boosted to a higher energy level and transferred to primary electron acceptor
Light harvesting complex
transfers electrons to the reaction center
Primary electron acceptor
accepts excited electrons and is reduced
What are the two types of photosystems within the thylakoid membrane?
Photosystem I and Photosystem II
Functions first and absorbing a wavelength of 680
P680 and P700
Reaction center chlorophyll A of Photosystem II and I
After photosystem II and absorbs wavelength 700
Where is the concentration of H+ greater in the chloroplast?
-The Thylakoid space
-The Stroma has a lower concentration of H+
Where is ATP synthase located in chloroplasts?
Within the Thylakoid membrane
What is the final electron acceptor of the light reactions?
What is the light independent reaction called?
What are the three phases of the Calvin Cycle?
Regeneration of the CO2 acceptor
How does the Calvin Cycle differ from the Krebs Cycle?
The Calvin Cycle is anabolic (creates G3P)
CO2 enters the cycle and is bonded with RuBP
Reduction and phosphorylation occurs with 3 phosphoglycerate and creates glyceraldehyde 3-phosphate
Some G3P is taken and is rearranged/phosphorylated with ATP, regenerating RuBP, the initial CO2 receptor of the Carbon Fixation phase
What are the products of the Calvin cycle?
ADP, G3P, NADP+
What is the initial acceptor of the Calvin cycle?
What is the importance of the Calvin Cycle?
The creation of G3P, which is later used to create glucose
-he used bacteria to determine what segments of the algae were releasing the most O2
-Violet blue and Red is the most effective