Biology, Test #2
NAD (Nicotinamide Adenine Dinucleotide)
organic molecules that cells make from the vitamin niacin and use to shuttle electrons in redox reactions
C3 photosynthesis
second name for calvin cycle because of the 3- carbon sugars it generates
stroma
site of sugar production from CO2
1st stage of cellular respiration takes place in
small intestine
exergonic reactions
spontaneous chemical reactions that release energy (product contains less energy than reactant)
grana
stacks of thylakoid sacs (think solar panels)
denatured enzymes change in shape, especially at the active site. as a result...
substrates, cofactors or coenzymes would not be able to bind to the enzyme.
1st stage of photosynthesis
sunlight is captured by photosynthetic cells
2nd stage of photosynthesis
sunlight is used to generate ATP
2nd stage of cellular respiration
Glycolysis (anaerobic) ... food molecules (especially glucose) are broken down and their atoms are rearranged into pyruvate, which in turn is converted into acetyl-coenzyme A.
in cellular respiration, the e- travel
down hill from glucose to the water, giving up their e to ATP
exergonic reactions release energy to...
drive endergonic reactions in the cell
in anabolic metabolism
each reaction in dehydration synthesis releases a water molecule and requires energy input
Redox RX release energy when....
electrons 'fall' from hydrogen carrier to oxygen (releases energy). these e- then pass from molecule to molecule in an energy cascade or electron transport chain
in absence of 02..
electrons trapped in glycolysis will then be added to pyruvate, forming lactic acid
photosystem 1: P700
energy electrons from photosystem 11 are passed to 1, which when activated by sunlight, produces electron carrying molecules called NADPH
kinetic energy
energy of motion, of matter that is moving
anaerobic respiration
metabolic reactions that can be conducted in the absence of oxygen.
lactic acid causes
muscle soreness
endergonic reactions
non-spontaneous chemical reactions that require energy input. (products contain more energy than the reactants)
cofactor
nonprotein molecules, usually ions or metals. Help enzyme achieve optimum efficiency
where do 3rd stage krebs cycle reactions occur?
on the inner membrane of the mitochondria, facilitated by enzymes.
oxygen is often used for purpose of...
releasing energy (such as ATP) from the reaction
glycolysis
the breakdown of glucose by enzymes, releasing energy and pyruvic acid.
which two stages are light-dependent reactions? (light reactions)
the first two stages
chemical reactions
the making and breaking of chemical bonds, leading to changes in the composition of matter
enzymes can be denatured very easily because...
they are made of proteins which are made of amino acids linked by peptide bonds.
which stage occurs in absence of light? (dark reactions)
third stage
stomata
tiny pores on the leaf that allows passage of CO2 (enters) and O2 (leaves)
mesophyll
tissue of leaf that contains chlorophyll
chloroplast
Site of photosynthesis
1st law of thermodynamics
energy cannot be created or destroyed, only transformed from one kind to another.
most enzymes end in what phrase
'ase'. (ex. sucrose --- sucrase, lipids --- lipase, etc).
Transformations are inefficient....
... they generate heat.
Process of Glycolysis produces...
2 ATP molecules
how many ATPs are produced for each FADH2
2 ATP's
how many ATPs are produced for each NADH
3 ATP's
Total number of ATP generated in cellular respiration
36
cellular respiration is broken down into...
4 stages
each ATP molecules contains:
5-C ribose sugar, an adenine (base), and three phosphate groups.
reactants
A starting material in a chemical reaction
Calvin cycle
ATP energy and hydrogen atoms from NADPH molecules are fed into and then carbon from CO2 and H from NADPH to form sugars, proteins and DNA.
3rd stage of photosynthesis
ATP is used, along with absorption of CO2, to produce oxygen and organic molecules
sunlight is captured to produce
ATP, oxygen, and organic molecules for other living things to survive
photosynthesis equation (CO2 fixation)
CO2 + H2O > glucose + H2O + O2
enzymes
Catalysts for chemical reactions in living things.. speed up reactions
4th stage of cellular respiration, ATP production, place of occurrence
Electron transport chain, electron transport system (ETS) (aerobic)... a sequence of chemical reactions that will accept the high energy electrons from the Krebs cycle and with the input of 02, generates about 32 ATP molecules. takes place in the inner membrane of the mitochondria.
products
Ending materials in a chemical reaction.
3rd stage of cellular respiration
Krebs cycle (aerobic)... series of 9 chemical reactions that run in a loop. each cycle requires the input of 1 acetyl- coA and will generate 8 high energy electrons in the electron transferring molecules.
autotrophs
Organisms that make their own food (plants, algae)
2nd mechanism that generates ATP
Substrate level phosphorylation... an enzyme transfers a phosphate group from a substrate to ADP to make ATP. Adds phosphate to ADP to make ATP, requires energy, comes from H gradient.
energy
The capacity to do work (to move matter against an opposing force or to rearrange matter).
active site
The part of an enzyme or antibody where the chemical reaction occurs.
2nd law of thermodynamics
The principle whereby every energy transfer or transformation increases the entropy of the universe.
entropy
a measure of the disorder of a system
each catabolic reactions requires..
a water molecule and release energy
enzymes lower...
activation energy (energy necessary to start a reaction), resulting in a conservation of energy
ATP
adenosine triphosphate (nucleotide) main energy source that cells use for most of their work
most reactions in human cells are
aerobic.
potential energy
capacity of mater to do work
1st mechanism that generates ATP
chemiosmosis... production of ATP using energy of Hydrogen ion gradients across the membrane to phosphorylate ADP.
thylakoids
chlorophyll is located with in disc like membraneous sacs
sunlight is captured by.... forms .....
chlorophyll, forming network called photosystem, located in the membrane of thylakoids
glycolysis occurs in _______, while krebs and ETC occur in ________
cytoplasm, inner membrane of mitochondria (cristae foldings)
anabolic metabolism uses...
dehydration synthesis reaction to build large molecules from small molecules
photosynthesis vs cellular respiration
energy storage vs. energy release, chloroplasts vs. mitochondria, in photosynthesis, H2O is split, yielding O2. H2O molecules are oxidized (lost e-) giving up their electrons and H+ ions. CO2 is reduced to glucose as e- and H+ is added to it. CO2 > sugar.
cellular respiration is
exergonic (produces/releases energy)
chemical energy
form of PE stored in arrangement of atoms in molecules
enzymes are made of
globular proteins (spherical protein)
most metabolic reactions in human cells require oxygen, exceptions include a reaction in cellular respiration called
glycolysis
chlorophyll
green pigment that absorbs light energy
Factors that could affect or denature enzymes:
heat, radiation, electricity, certain chemical substances, and extreme PH
catabolic metabolism uses...
hydrolysis (decomposition) reaction to break up large molecules into smaller molecules
1st stage of cellular respiration
hydrolysis... macromolecules are broken down into monomers using decomposition reactions occurring in the cytoplasm. (water breaks polymer, forms two separate monomers) doesn't require oxygen in cytoplasm
oxidation-reduction reaction (aka redox reaction)
involved partial or complete transfer of one or more electrons from one reactant to another.
cellular respiration is a Redox process
involves both oxidation and reduction
heat is poor kind of energy to do work because...
it is lost to the environment
heat
kinetic energy associated with randomly moving molecules
what happens when ATP turns into ADP
large amounts of kinetic energy are released
photosynthesis
light energy of the sun is converted into chemical energy stored in organic molecules.
glucose is oxidized by....
loosing hydrogen
energy conversion results in
loss of useful energy (heat)
producers
make organic food molecules from very simple raw materials. (plants)
denatured
melt/breakdown
Aerobic respiration
metabolic reactions that are conducted in the presence of oxygen
photosystem 11: P680-
one of two light-capturing units in a chloroplast's thylakoid membrane or in the membrane of some prokaryotes; thykaloids capture light energy and electrons from water molecule, produces ATP and oxygen in ETC
coenzyme
organic cofactors such as vitamins. help enzyme achieve optimum efficiency
cellular respiration is a series of metabolic reactions where molecules are...
oxidized (broken down, burned, melted) to generate energy for various cellular activities.
substance that looses e- is _____ and acts as _____
oxidized, reducing agent (electron donor) to the substance that gains electrons
ATP energizes other molecules by
phosphorylating them
mitochondria is found in all living things except
photosynthetic cells where chloroplasts are present.
(fuel for cellular respiration)
polysaccharides, sugars. fat, glycol and fatty acids. proteins, amino acids.
cellular respiration
process of breaking down food molecules and generating ATP energy in organelles called mitochondria.
fermentation
process of bypassing aerobic respiration and producing small amount of ATP from glycolysis
heat
random molecular motion
substrate
reactant of an enzyme-catalyzed reaction
by gaining electrons, a substance is ______ and acts as an ______
reduces, oxidizing agent (electron acceptor)
purpose of krebs cycle...
to produce NADH/FADH (high energy electron carriers). donates electrons of H atom and 2 ATP
in photosynthesis, the e- travel
uphill, from h2O to glucose, adding light energy captured by chlorophyll.
phosphate groups have negative charges, making the 2 chemical bonds in between these 3 phosphates contain large amounts of energy in order to hold them together. What happens when all the strong bonds are broken?
when the last high energy chemical bond is broken, ATP is now converted into ADP