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158 Cards in this Set
- Front
- Back
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What is energy? |
the capacity to do work |
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What does work mean? |
work is a force over a distance |
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What does kinetic energy mean? |
-the energy of motion
- falling down stairs |
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What does potential energy mean? |
-stored energy
-also the bonds in foods
-you are at the top of the stairs |
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What are some forms of energy? |
mechanical, electric current, heat, light, chemical |
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Most forms of energy can be converted into _______ ________. |
heat energy |
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Heat energy is measured by ________ |
kilocalories |
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kilocalories = |
capital Calorie |
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Heat energy units are in ______ |
lower case calorie |
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One calorie = |
the amount of heat required to raise the temperature of 1 gram of water by 1 degree celcisus. |
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1 kilocalorie = |
1000 calories |
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Potential energy stored in chemical bonds can |
be transferred from one molecule to another by way of electrons |
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What does oxidation mean? |
loss of electrons |
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What does reduction mean? |
gain of electrons |
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What does redox reaction mean? |
-oxidation and reduction are coupled to each other
- LEO goes GER |
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What is the First Law of Thermodynamics? |
-Energy can not be created or destroyed -energy can only be converted from one form to another -example sunlight goes to chemical energy with photosynthesis |
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What is the Second Law of Thermodynamics? |
disorder is more likely than order; energy moves from higher organized state to a lesser organized state |
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What is entropy? |
disorder in the universe |
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Second Law of Thermodynamics states |
that entropy is always increasing |
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What is free energy? |
-the energy available to do work -denoted by the symbol G (Gibb's free energy) |
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What is enthalpy? |
energy contained in a molecule's chemical bonds |
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Chemical reactions can |
create changes in free energy |
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When products contain more free energy than reactants - Change in G is positive |
A + B produces AB 1+ 1 should equal 2 but it could be 4 with more free moving energy in the product -energy came in |
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When reactants contain more free energy than products - change in G is neagtive |
A + B produces AB -energy is released so product is lesser than the reactants
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What kinds of transfer energy are there? |
endergonic reaction exergonic reaction |
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What is endergonic reaction? |
a reaction requiring an input of energy - change in G is positive |
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What is exergonic reaction? |
a reaction that releases free energy - change in G is negative |
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What are some energy sources that can start a reaction? |
activation energy and catalysts |
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What is activation energy? |
extra energy needed to get a reaction started - destabilizes existing chemical bonds - requires even for exergonic reactions |
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What is a catalyst? |
its job is to be a substance that lowers the activation energy of a reaction |
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What is ATP? |
adenosine triphosphate - energy "currency" of cells
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What is the ATP structure? |
ribose, a 5 carbon sugar adenine three phosphates |
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ATP stores energy in the |
bonds between phosphates |
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Phosphates are highly negative , therefore: |
-the phosphates repel each other - much energy is required to keep the phosphates bound to each other - energy is released when the bond between two phosphates is boken |
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When the bonds between phosphates are broken: |
ATP turns into ADP + Pi also energy is released - to make ADP+Pi turn in to ATP it must consume energy |
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What is ADP? |
adenosine diphosphate |
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What is P little i? |
inorganic phosphate -this reaction is reversible |
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Energy released when ATP is broken down to ADP can |
be used to fuel endergonic reactions |
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Energy released from an exergonic reaction can |
be used to fuel the production of ATP from ADP+Pi |
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What is an enzyme? |
-molecules that catalyze reactions in living cells -most are proteins -lower the activation energy required for a reaction -are not changed or consumed by the reaction |
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What is a catalyze? |
helps reaction occur |
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What does activation energy do? |
pushes to start a reaction |
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What is denature? |
the unfolding of a protein |
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Enzymes are like |
you start pushing a huge rock up a hill by your self then other people come to help. |
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What is a substrate? |
-a molecule that will undergo a reaction -its like a reactant |
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What does active site mean? |
-region of the enzyme that binds to the substrate -shape is important |
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What happens when a substrate lands on the active site? |
The enzyme changes shape, that is called an induced fit |
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True or False Enzymes cannot be used more then once |
False, enzymes can be used over and over again unless environment changes |
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What does multienzyme complex mean? |
globs working together as one unit |
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What are the advantages of a multienzyme complex have? |
1. The product of one reaction can be directly delivered to the next enzyme 2. The possibility of unwanted side reactions is eliminated 3. All of the reactions can be controlled as a unit |
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How are multienzymes complex are like a mall? |
Because you can get everything in one places at the mall and everything happens in one place in a multienzyme complex |
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What is the most complex enzymes we know of? |
-pyruvate dehydrogenase -60 protein subunits |
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What is a ribozymes? |
-RNA with enzymatic abilities -not a protein |
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What affects enzymes to change shape? |
the environment like : pH, temperature, regulatory molecules |
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What change of shape causes? |
its function to change |
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When does enzyme activity stop increasing in temperature? |
when it reaches temperature optimum |
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What happens if temperature go too far above the temperature optimum? |
Can denature the enzyme, destroying the function |
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What range is good to put an enzyme in a pH solution? |
6 to 8 pH |
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What does inhibitors mean? |
-They are molecules that bind to an enzyme to decrease enzyme activity.
There are two types |
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What is does competitive inhibitors mean? |
compete with the substrate for binding to the same active site |
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What does noncompetitive inhibitors mean? |
-bind to sites other than the enzyme's active site -like a light switch |
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Where are allosteric enzymes? |
-exist in either an active or inactive state -they turn on or off -they bind to the allosteric site |
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What are allosteric inhibitors? |
-they bind to the allosteric site to inactive the enzyme -turn it off |
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What are allosteric activators? |
-bind to the allosteric site to activate the enzyme -turn it on |
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Allosteric means? |
other than the active site |
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What does metabolism mean? |
-all chemical reactions occuring in an organism -happens in enzymes |
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What does anabolism mean? |
-chemical reactions that use energy to make new chemical bonds -example: photosynthesis -this ANd this ANd this ANd |
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What does catabolism mean? |
-chemical reactions that release energy when bonds are broken -example: cellular respiration -cats scratch things up and break things |
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Some enzymes require additional molecules for proper enzymatic activity such as: |
cofactors or coenzymes |
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What is a cofactor? |
-usually metal ions, found in the active site participating in catalysis -example: iron catabolism to break down |
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What is a coenzyme? |
-nonprotein organic molecules, often used as an electron donor or acceptor in a redox reaction -example: vitamins anabolism |
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What does biochemical pathways mean? |
-is a series of reactions in which the product of one reactions becomes the reactant in the next reaction
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Biochemical pathways are often regulated by feedback inhibition which are? |
-feedback inhibition stop the production |
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What types of chemical energy are there? |
Autotrophs and Heterotrophs |
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What are autotrophs? |
-self-feeders; organisms capable of making their own food -example: Plants, algae, some bacteria, and prokaryotes |
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What are heterotrophs? |
-other-feeder; gains energy from consuming food and using the stored chemical energy found in the bonds of food -most organisms are heterotrophic |
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Chemoautrophs are |
Archea, metals |
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Photoautrophs are
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things like plants
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What is the process of harvesting stored chemical energy?
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digestion
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What is digestion?
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Hydrolytic reactions involving enzymes that break large molecules into smaller molecules
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Catabolism takes place in?
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Happens in stored energy in the bonds is release
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What is chemical energy?
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-potential energy of bonds is harvested by breaking bonds and transferring electrons during redox reactions
-some energy is used to make new bonds -some energy is lost as heat |
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What is one way energy is used?
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ATP synthesis
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What are electron carriers?
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-specialized molecules that carry high energy electrons to Oxygen
-example: NAD+ carries high energy electrons to other molecules as NADH |
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ATP is used by most cells to do?
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work by transferring captured energy during cellular respiration
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ATP drives what kind of chemical reactions?
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endergonic chemical reactions
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Where is energy stored in ATP?
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the phosphate bonds
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What are 2 ways of synthesizing ATP?
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1. Substrate level phosphorylation
2. Chemiosmosis |
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What is Substrate Level Phosphorylation?
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-adding a phosphate group to ADP
-occurs during glycolysis -PEP = phosphoenolpryruvate -PEP is transferred to high energy phosphate to ADP |
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What is Chemiosmosis?
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-ATP made using enzymes and a proton gradient (build up of Hydrogens) created in the Electron Transport Chain
-Occurs within the inner membrane of the mitochondria with aid of ATP synthase powered by a proton gradient |
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What are the three types of respiration in Cellular respiration?
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1. Aerobic
2. Anaerobic 3. Fermentation |
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Aerobic Reactions has four steps to make 30+ ATP and they are:
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1. Glycolysis
2. Oxidation of Pyruvate to acetyl CoA 3. Krebs Cycle 4. Electron Transport Chain |
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The four steps look like:
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C6H12O6 + 6O2 ---> 6CO2 + 6H2O + 30+ATP
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Glycolysis
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-occurs in all cells in the cytoplasm
-also is apart of anaerobic -breaks down to 2 pyruvate -makes 2 ATP |
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G3P is oxidized to become _____?
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pyruvate
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Electrons released are gained by NAD+ to make?
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-NADH
-makes 2 NADH in glycolsis |
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Net energy of glycolsis is:
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2 ATP and 2 NADH
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Oxidation of Pyruvate
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-occurs within the region between inner and outer membrane of mitochondria in eukaryotes
-in prokaryotes this happens in the cytoplasm -Within the mitochondria each pyruvate loses a Carbon |
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What is the term for losing a Carbon?
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Decarboxylation
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2 electrons lost from oxidation of pyruvate are picked up by
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-2 NAD+ to become 2 NADH
- trace lost electrons as picked up Hydrogens |
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When pyruvate minus a carbon equals
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-acetyl group that bonds with a coenzyme to become Acetyl CoA
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Oxidation of pyruvate's net energy is
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2 NADH
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Krebs cycle
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-occurs within the matrix of the mitochondria
-requires oxygen -2 acetyl groups enter the mitochondria with help of coenzyme A |
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Kreb cycle generates
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-2ATP, 6 NADH, 2 FADH2 and 4 CO2
-acetyl groups recombine with 4 Carbons to form citrate (a 6 Carbon compound) |
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Krebs Cycle happens how many times/
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-2 times
-makes a lot of carriers -small amount of ATP |
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Electron Transport System
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-NADH carries electrons to the inner mitochondria membrane
-FAD2 is attached to inner membrane -there are 3 protein complexes embedded in the inner membrane |
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Electrons pass among each protein like a relay race
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-energy is released
-the released energy is used to transport protons (Hydrogen's) in the intermembrane space to make a proton gradient |
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At the end of the Electron Transport System
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O2 accepts the electrons and used energy to form water
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ATP formation of chemiosmosis
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-the high proton (H+) concentration in the intermembrane spaces drives the proton back into the matrix by diffusion
- ATP synthase (enzyme) |
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ATP snythase
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used the gradient to add Pi to ADP to make ATP
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Regulation of ATP production
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-feedback inhibition occurs when the level of ATP is high enough
-when ADP is high, enzymes are activated for the production of ATP |
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Anaerobic respiration
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-occurs without oxygen
-examples: muscle cells, bacteria, and yeast are organism that use anaerobic respiration |
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The 2 main steps of Anaerobic respiration are:
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1. Glycolysis
2. Fermentation |
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What is fermentation used for?
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making breads, yogurt, beer, and wine
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What are the 2 types of fermentation?
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1. alcoholic fermentation
2. lactic acid fermentation |
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Alcoholic Fermentation uses:
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1. Glycolysis (makes some NADH)
2. each pyruvate will lose a Carbon to create 2 carbon dioxide molecules (bubbles in sodas) 3. Hydrogens from NADH are donated to an organic compound to form ethanol -Net yield is 2 ATP |
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Lactic Acid Fermentation
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-muscle cells generate 2 pyuvate by glycolysis
-lacking oxygen, the pyruvate will be reduced by NADH to form lactic acid -NAD+ created is cycled back into glycolysis -muscle soreness, fatigue will occur if not removed -Net yield is 2 ATP |
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What is another Anaerobic respiration type?
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-Chemoautotroph-inorganic molecule is the final electron acceptor -example: carbon dioxide and sulfur-Methanogens (archaea) used carbon dioxide as final electron acceptor and form methane and is released in landfills
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What is photosynthesis?
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-anabolic form of metabolism; forming new bonds requires energy input
-light energy is captured and converted into chemical energy in the form of glucose and ATP |
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When redox reactions happens in photosynthesis what is oxidized and reduced?
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water is oxidized and carbon dioxide is reduced
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What are examples of things that undergo photosynthesis ?
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-plants
-algae -and some bacteria -phito planton feed organisms in ocean to reduce carbon dioxide |
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What is the chemical equation for photosynthesis?
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6CO2 +12 H2O + light produces C6H12O6 + 6H2O + 6O2
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Where does photosynthesis happen?
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-plant leaves, in the mesophyll cells (the middle layer)
-chloroplasts are found in the middle layer |
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What do the Upper and Lower epidermis of leaves serve for?
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it has a protective role
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Lower epidermis contains stomata
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-stomata allow gases and vapor exchange
-these gases and vapors are products of photosynthesis |
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What is one major role in adding water to the atmosphere by plants?
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transpiration = adding water to the atmosphere by plants
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Stroma vs. Stomata
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Stroma: building blocks, roma like rome the structures
Stomata: opening |
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Chloroplasts
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-where photosynthesis occurs
-double membrane and own DNA -internal membranes are folded into structures called thylakoids |
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Thylakoids hold the photosynthetic pigments
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are used to capture light energy
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pigments do what
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-absorb wave lengths of light energy
-color we see is what is not absorbed by reflected |
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How are thylakoids are organized?
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they are organized into stacks called granum
plural is grana |
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Thylakoids are surrounded with?
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stroma
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stroma contains enzymes needed to
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synthesize organic molecules like glucose and other sugars
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What are photons?
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-light energy that moves in waves
-light is part of the electromagnetic spectrum (EMS) -absorbed energy is converted to heat or can change energy levels in molecules |
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ROYGBIV
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Red is lower in energy but longer in waves lengths
versus Violet that is high in energy but shorter waves lengths |
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Where are pigments found?
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-in the chloroplasts
-several pigments work together to form a photosystem -each type of pigment is capable of absoring a certain wavelength of light energy delivered by a photon of light |
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Important pigments needed for photosynthesis are:
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chlorophyll a and b
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Why do we see green?
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-they absorb the blue-violet and red range wavelengths
-reflect the green range |
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What are accessory pigments
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carotenoid (yellow) and xanophyhylls (orange)
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What are the 2 types of systems connected by an electron transport system?
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-Photosystems: antenna complex and reaction complex
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What makes up the antenna complex?
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-clusters of pigmenss and proteins held together in the thylakoid membrane
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How does a photosystem work?
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-captures a photon energy-passes this energy through a series of molecules and ends with a special chlorophyll molecule (leader) in the reaction center-excited electron is then ejected to an acceptor
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What is the reaction center in the photosystem?
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-transmembrane protein-pigment complex that uses the energy to move excited electrons to an acceptor
-water is oxidized and produces oxygen and the electrons are used to replace the ejected electron from the reaction center -water becomes an electron donor |
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Photosynthetic Reactions
there are 2 parts to photosynthesis and they are: |
1. photophosphorylartion
2. calvin cycle |
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What is photophosphorylation?
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-a 2 stage process in which ATP and NADPH are formed
-this includes chemiosmosis -oxygen is released -light dependent |
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What is the calvin cycle?
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-uses ATP and NAPH from the first step to form sugars from carbon dioxide
-non-light dependent -aka the dark reactions |
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Photophosphorylation used 2 photosystems:
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-photosystem 1 and 2
-photosystem 2 is first and photosystem 1 in next -occurs in the thylakoid membrane |
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Photosystem 2
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-photon energy excites the primary pigments that passes high energy to the next molecule until it reaches a final electron acceptor
-the lost electron is replaced from the splitting of water and forms oxygen -oxygen is expelled through the stroma in the leaf |
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The electron is passed to a proton pump complex
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the b6-f complex pumps hydrogens from the stroma into the inner thylakoid space that created a proton gradient (chemiosmosis)
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ATP synthase pumps hydrogens out of this spaces and ADP
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is phosphorylated to ATP (chemiosmosis)
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Photosystem 1
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-photon energy excites the electron again
-when excited it leave to the fd protein so it can reduce NADP |
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Making NADPH
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-2 molecules of fd donate their high energy electrons from NADPH with aid of the enzyme NADP reductase
- When the NADP picks up the hydrogen, this contributes to the proton gradient difference between the thyakoid space and the stroma |
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Melvin Calvin
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-won the Nobel prize in chemistry
-completed pathway of carbon in the photosynthesis |
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Calvin cycle (aka the dark reaction)
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-light independent or carbon fixation (bonding carbons)
-Binds carbon dioxide to form sugars and uses ATP and NADPH from the light dependent reactions -occurs in the stroma |
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Carbon fixation
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carbon dioxide is bonded to an organic 5 carbon compound RuBP (ribulose 1, 5 biphosphate)
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Through a series of reactions, fueled by ATP and NADPH the PGA is reduced
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to become G3P
-2 G3P bond to make glucose |
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How many times does a calvin cycle turn?
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6 turns to make one molecule
-helpful hint the 6 in C6H12O6 in the glucose molecule |
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excess G3P is converted to :
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strach
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