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105 Cards in this Set

  • Front
  • Back
Organisms obtain nutrients from the environment
types of nutrition
carbohydrates, lipids, proteins
oxygen, water, etc.
organisms release energy from food in a controlled way
the ability to do work
types of energy
chemical energy
free energy
chemical energy
enregy stored in chemical bonds of glucose, glycogen, lipids etc.
free energy
energy readily availabe to do work, which we keep on hand as ATP
Types of energy molecules
Adenosine Triphosphate
-stores energy in phosphate bonds
-usable form of energy for calls
-must be in constant supply or cells die
adenosine Diphosphate
-leftover when ATP bonds are broken and energy is relased
-when new energy is available, AP is reformed from ADP and phosphate
Adenosine Monophosphate
-in desperate situations cells will break a second phosphate bond
-not as much energy released as ATP --> ADP
types of metabolism
-uses ATP to synthesize molecules
Makes ATP during degradation
Uses of cellular energy
maintaining homeostasis
head (wasted energy)
-protein synthesis
-building necessary cell parts
-active transport across membranes
-movement of cells and organelles
What is cellular respiration?
-the most efficient way for organisms to obtain energy stored in nutrients
-Raw materials are carbohydrates, lipids, and proteins
-Stepwise series of catabolic reactions
equastion for cellular respiration
C6H12O6 + 6O2 --> 6CO2+ 6H2O + energy

glucose + 6oxygen --> 6carbon dioxide + 6water + energy
Glycolysis (definition)
The break down of sugar (glucose) in the cytoplasm)
Types of respiration
Aerobic respiration
requires oxygen
Anaerobic respiration
does not requite oxygen;
simpler, and produces less energy than aerobic
3 things that happen in glycolysis
(both aerobic and anaerobic)
-molcule of glucose is broken in two
-ATP is formed (net 2)
-hydrogen available for electron transport
Step 1 of glycolysis
Glucose enters the cell and is converted into the form for the reactions--> thsi uses 2 ATP molecules
Where does Glycolysis take place?
Cytoplasm/ cytosol
Step 2 of glycolysis
The prepared 6-C molecule splits into two 3-C phosphates called PGAL
Step 3 of glycolysis
PGAL is rearranged to form another 3-carbon compound called pyruvate
What is te end product of glycolysis?
What is the end results of glycolysis?
-2 pyruvate are formed from each glucose molecule
-4 ATP molecules are produced, for a net product og 2 ATP from glycolysis
-hydrogen ions and electrons are produced which are carried away by NAD+; the product released is 2NADH
What is the biological role of glycolysis
to produce ATP, NADH, and pyruvate
What are the reactants in cellular respiration?
ATP, NADH, pyruvate
What process happens after glycolysis in anaerobic respiration
What happens in fermentation
-produced no further ATP
-regenerates NAD+ from NADH for glycolysis to continue, thus producing minimal ATP-2 per glucose
-pyruvate is converted into lactate
(a. lactic acid fermentation in animals
b. causes muscle soreness
c. continues until oxygen becomes available)
-alcoholic fermentation occurs in bacteria and come fungi; this is the entire process of cellular respiration in these organism
What happens after glycolysis in aerobic respiration?
-pyruvate is transporte to the mitochondria
-pyruvate is broken up to produce CO2 and acetate (a 2-carbon organic acid)
-acetate gets picked up by coenzyme A and together they form acetyl CoA, which will go to the Krebs Cycle
-Another NADH is produced
What are the structure and function connections of the mitochondria and respiration?
-outer and inner membrance systems
-the cristae, or foldings of inner membrane contain enzymes for electron transport, ATP formation, and the Krebs cycle reactions
-the outer membrane controls movement in and out of the mitochondria
-the martix, or empty space, contains most of the enzymes for the Krebs cycle
What is the location of Krebs cycle and electrons transport system?
What is another name for the mitochondria
Powerhouse of the cell because it is where most ATP synthesis occurs
How many mitochondria can a cell have?
several thousand
What is another name for the Kerbs Cycle
The Citric Acid Cycle
What is the Krebs Cycle?
-Starts where glycolysis ends when oxygen is present, thus a component of aerobic repiration
-technically begins after pyruvate is converted to acetyl CoA
-conversion lumped with Krebs Cycle for purpose of tracking reactants and products
-conversion does not take place in the mitochondria
What are the reactants of the Krebs Cycle?
1acetyl CoA per glucose molecule
-8NAD+ and 2 FAD
-3 molecules of O2
-recycled 4C compound called oxaloacetate
What are the products of the Krebs cycle
2ATP (4 total)
8NADH and 2 FADH2
- 6molecules of CO2
What is the Electron Transport System
-component of aerobic respiration, using oxygen
-produces the most ATP (thats its purpose)
-Involves a series of electron carriers (enzymes and other proteins called cytochromes) in the cristae of the mitochondria
Location of the Electron Transport system
critae of the mitochondria
Step 1 of the ETS
Carrier molecules (NADH and FADH2) bring electrons to the chain via hydrogen
Step 2 of the ETS
Hydrogen atoms are split into protons and electrons
-thsi is the top of the chain
-the elctrons at this point have high energy
Step 3 of the ETS
-Electrons are transferred along a series of substances, releasing energy at each step
step 4 of the ETS
-some free energy is used to actively transport the protons, producing an electrochemical concntration gradient
-protons diffuse down the concentration gradient, passing through the enzyme ATP synthetase
-this triggers the conversion of ADP to ATP
How is the energy released in the ETS captured?
in the form of ATP
What is the total ATP produce?
32-34 molecules of ATP
What does the final electron acceptor, or terminal cytochcrome do?
-recombines electrons with hydrogen ions
-bonds hydrogen atoms to oxygen
-3O2 needed
-6h2O needed
What do Lipids in the Krebs-Cycle in Non-Carbohydrate Metabolism do?
-fatty acids break down into acetyl CoA enters krebs cycle as usual
What do proteins in the Krebs Cycle in Non-carbohydrate metabolism do?
-amino groups are detached from carbon skeletons
-carbon chains converted to acetate which enters krebs cycle as usual
What is the control of respiration?
-high demand for energy
-cells use glucose in bloodstream to make ATP
-if blood glucose levels are low, stored glycogen is broken down (stored in the liver)
-stored protein and fat are last resorts
What happens when there is a low demand for energy in respiration?
-cells do not need all of the glucose present in the blood immediately
-glucose is converted to glycogen
-if excess glucose is present, the remainder will be stored as fat
relationship of Respiration and photosynthesis
-the products of photosynthesis (sugar and oxygen) are the reactnts for respiration
-the products of respiration (water and carbon dioxide) are the reactants for photosynthesis
What are some parallels between respiration and photossynthesis
-both systems utilize electron transport to synthesize ATP, but with variatrions
-both occur in membranous organelles
-both have membranes outsdide and structure inside
Leaf structure
-the green leaves of plants function to trap sunlight and utilize the energy to perform photosynthesis, which produces food for the plant. The leaves are designed to maximize photosyntheis.
-wide blade
-chloroplast streaming
-individual pigment rotation
Anatomy of a leaf
-guard cells
waxy coating to prevent water loss
pores for gas and water exchange
guard cells
surround and control stomate operation
middle area where photosynthesis takes place
spongy layer of the mesophyll
lower layer which is more loosely packed so CO2 can move through to upper layer
palisade layer of the mesophyll
upper laywer which is more tightly packed
-chloroplasts move around cells in both
-evaporation of water from leaf
-controlled by guard cells
-excess water in guard cells causes them to swell
-swelling of guard cells opens stomates
chloroplast streaming
-chloroplasts circle in leaves to ensure equal access to light and optimize photosynthesis
-individual thylakoid membranes are full of migrating pigments
Chloroplast structure
-internal membrane system
-flattened sacs
-stacks of thylakoid membranes
-maximize surface area for capturing sunlight
-liquid solution around thylakoids
pigments of a leaf
chlorophyll A and B
xanthrophyll (yellow
carotenoids (red and orange)
Formula for photosynthesis
6co2 + 6h2o --> c6h12o6 + 6o2

6 carbon dioxide + 6 water --> glucose + 6 oxygen
What is necessary for photosynthesis?
light and chlorophyll
What are the 2 processes of photosynthesis?
-light reactions
-calvin cycle
What are the ligh reactions?
-absorption of light energy
-conversion of light energy into chemical energy
What is the calvin cycle?
-storage of chemical energy in sugars
-completion of reaction:
3co2 + 3h20 --> c3h6o3 + 3o2
Step 1 of the light reactions
-light hits leaves
Step 2 of light reactions
-groups of pigments colectively called photosystems absorb the light energy
-Photosystems I and II
Step 3 of the light reactions
-the energy fromt he light is used to split water molecules; a process called photolysis
What happens to the water in th light reactions?
-water is split into elemental oxygen
-oxygen is relesased from the plant
-electrons travel through an electron transport chain, where they are energized higher
how much oxygen is released from the plant?
6 molecules of water go in
3 molecules of oxygen go out
Why do the elctrosn travel through an electron transport chain?
-electrons freed form the splitting of water are transported from PSII to PSI via carriers
-photons of light excite electrons to a higher energy level as they arrive as PSI
Who do the electrons need to be energized
-energy from the elctrons is used during transport
-this depletes the electron's energy, thus requiring re-energizing
-energy is used to pump protons into the thylakoid
How is the electron transport chain in photosynthesis similar to the ETS in respiration?
-pumping of hydrogen ions produces an electrochemical gradient
-Gradient causes hydrogen ions to diffuse out of membrane
-Diffusion occurs througha protein channel called ATP synthetase and triggers the formation of ATP from ADP
What is the end product of the light reactions?
-hydrogen and electrons are carrie to the next phase by NADP, and electron acceptor
(NADP + H+ + e --> NADPH)
-ATP is produced during the process
(ADP + Pi --> ATP)
-source of energy for the Calvin Cycle
What carries the end products to the calvin cycle?
General information abtou the Calvin cycle
-does not require light energy directly
-requires products of light reactions (ATP & H)
-occurs int he stRoma of the chloroplast
-Step 1 of the Calvin cycle
co2 + RuBP --> 2PGA
-RuBP is a recycled 5C compound, simlar to the oxaloacetate seen in respiration
-Carbon dioxide (1c) plus a 5-carbon compound form a 6-carbon sugar (NOT GLUCOSE)
-the 6-c sugar with the help of an enzyme (rubisco)- splits into two 3-c acids
Step 2 of the Calvin cycle
2PGA + 2ATP + 2NADPH --> 2PGAL + 2ADP + 2P + 2NADP+
-the two 3-carbon acids are converted into 3-carbon sugars by the addition of hydrogen
-PGA is converted to PGAL a 3-carbon sugar
Step 3 of the Calvin cycle
-10 out of every 12 PGAL created are sed to regenerate RuBP (keeps cycle going)
-2 out of every 12 PGAL created are released from Calvin Cycle
(this can create one c6h12o6)
-for every 6co2 one glucose moleule can be synthesized
What is the end product of the Calvin cycle?
What happens to the PGAL after released?
-PGAL may be enymatically converted to another 3-carbon sugar, two of which may combine to form a 6-carbon sugar, which can ultimately lead to glucose
-sugar may be converted to starch for storage purposes
-carbon skeletons may be conerted to starch for storage purposes
-carbon skeletons may be converted to lipids or proteins
What are characteristics of light-absorbing pigments that function in photosynthesis?
they are embeded in membranes
The products of the light reactions of photosynthesis are...
o2, NADPH, and ATP
Leaves of a plant appear to be green because
the leaves absorb only green wave lengths
In the light reactions of photosynthesis, light energy is absorbed by
water and given off as oxygen molecules
Chlorophyll and other pigments involved in photosynthesis...
absorb light and transfer its energy to the reaction centers
The smallest unit in which phtotsynthesis takes plase is the
In photosynthesis, light energy is absorbed by
chlorophyll and other pigments
Sugar phosphates are produced in the Calvin cycle. These compounds are used by the plant to make
Which is falce concerning photosynthesis and aerobic respiration?
both occur in specific organelles
In the presence of oxygen ___ molecules of ATP can be formed from a single glucose molecule
Which is a series of substances along which electrons are transferred?
Electron transport chain