Chapter 5 Flashcards
Sum total of all chemical reactions within a cell
Metabolism
Catabolism
Breakdown of complex organic molecules into simpler ones - energy is released (exergonic)
Anabolism
Building cooped organic molecules from simpler ones; energy is used (endergonic)
Redox
Oxidation and reduction reactions -electron transfer from an electron donor to an electron acceptor -reactions always occurs in simultaneously -cells use electron carriers to carry electrons - 3 important electron carrier -NAD+ NADP+ FAD –> FADH2
Enzymes in metabolism
Enzymes are organic catalysts -increase likelihood of a reaction 6 - categories of enzymes based on mode of action
Hydrolases, Isomerases, Ligases, Lyases, Oxidoreductases, Transferases
Enzymes are..
-organic catalyst
The Generized Equation
Catalyst
a substance that increases the rate of a chimical reation without itself under going a permant chemical change
Proteins which catalyze reations in cells by lowering the acctivation engergy (make reactions more efficient)
are not altered or destroyed during the reaction (can be used over and over)
exhibit specificity (they can drive one reaction but can’t drive a different reaction)
Enzymes
acted up on by the enzymes are called
substrates
maxiumum number of substrate molecules an enzyme molecule can convert to product each second is called
Turn over
Typcial turn over time
1 - 10,000 per second for each enzyme
protein portion of an enzyme is called
Apoenzyme
non-protein component is the
co-factor
Co-factor can be organic or inorganic
If a co-factor is a complex organic molecule, it is called a
coenzyme
when fully assembled they from the
holoenzyme
some enzymes are RNA molecules called
ribozymes
Factors influencing Enzyme rates
Temperature
pH
Substrate Concentration
Inhibition
Optimum temperature enzymes work in
37oC
98.6 oF
Optimum levels of pH
4-6
Where does a noncompetitive enzyme inhibitor bind?
On the allosteric site of the enzyme
In end product inhibition, what switched off the pathway?
Making excess product
Three way that energy is stored through formation of ATP
(ADP + P = ATP); the process is called
phosphorylation
direct transfer of phophate to ADP from phosphorylated subustrate
Substrate-level phophorylation
electrons transferred from organic compounds to electron carriers (NADH AND FADH2); energy is transferred down an electron transport chain which is then used to gerate ATP
Oxidative Phosphorylation
light energy is trapped and an electron transport chain is used to generate ATP
Photophosphorylation
making a total of 38 ATP for each glucose molecule
Three phases
splits glucose (6-carbon) in half making two (3-carbon) pyruvic acid molecules – process releases a small amount of enegy and small amount of NADH
“bridge step” akes us into mitochondria
Glycolysis
exracts energy from pyruvic acids (small amount) power is in the reduction of organic molecules like NADA and FADH2
Krebs Cycle
exracts lots of energy by oxidizing those carriers and using it to make ATP
Electron Transportation Chain
How many ATP does NADH make
3 ATP
How many ATP does FADH2 make
2 ATP
Also uses the electron transport chain but can’t enter at the first step..
Because of this it can only move 2 pairs of H+ and will ultimately be responsible for production of 2 ATP molecules
FADH2
Energy Yeild
….Electron Transport Chain
10 NADH =
2 FADH2 =
10 NADH = 30 ATP
2 FADH2 = 4 ATP
Final Electron is an inorganic molecule other than O2 (nitrous oxie, nitrate, methan)
This style of respiration is much less effecient than aerobic respiration, so organisms that do it produce less total ATP. Because of this, anerobic bacteria tend to grow slow than aerobes
Anaeroic Respiration in Prokaryotes
after glycolysis, the pyruvates can be further metabolized by takeing alternate pathways; what pathway is that?
Fermentation
- releases energy from sugars or other organic molecules
- does not requrie O2 (but can often occure in presence of O2)
- Does not use Krebs or Electron Transort Chains
- Uses an organic molecule for electron acceptor
- Produces few ATP (one or two per start molecule)
- End products containmuch or orginal energy (ethanol, lactic acid)
Fermentation
Ethanol (ethyl alcohol)
beer, wine, fuel
Acetic Acid
Vinegar
Lactic acid -
yogurt, sauerkraut etc…
Methane
Fuel
Fermentaion Test Medium contains:
Protein
(casein for us)
Fermentaion Test Medium contains:
one specific carbohydrate
maltose, fructose, glucse etc…
Fermentaion Test Medium contains:
pH indicator
color change if uses carbohyrates
Fermentaion Test Medium contains:
Durham tube
little glass tube to collect gas if it is produced
