Exam 2 pt 2 Flashcards
what are some ways to increase the rate of a reaction?
- using an enzyme lowers activation energy
- increasing temperature: not ideal due to high temperatures destabilizing H bonds between proteins and can make it lose its shape/active site
- increasing [substrate] - can only increase reaction until saturation pt of enzyme is reached
how does temperature and pH affect enzyme activity?d
enzymes have ideal temperature and pH
- at high temperatures, H bonds in proteins can break and active site of enzyme is lost
- different pH can cause protein to denature due to ions released from acids and bases interfering with H bonds of proteins
what are they types of enzyme inhibition?
competitive inhibition: inhibitor has similar conformation of the substrate of the enzyme and attaches to the active site of the protein to prevent rxn
- can be permanent loss of enzymatic activity or can be reversible by adding more of the substrate
non competitive inhibition: inhibitor binds to another part of the enzyme than the active site - allosteric site
- causes active site to change conformation so that it can no longer bind to the substrate
describe feedback inhibition. what type of inhibitions is it?
non competitive inhibitor
end product in a pathway can bind to almost eric site on an enzyme earlier in the pathway to prevent synthesis of substrates and products
what is sulfanilamide? what kind of inhibitor is it?
chemical similar to PABA
- bacterial enzyme that converts PABA into folic acid is inhibited by sulfanilamide
what are the two types of carbohydrate metabolism?
fermentation and cellular respiration
both pathways start with glycolysis
describe glycolysis. what is its major product?
splits glucose
- starts with adding 2 phosphate groups to raise energy of molecule
- 3 carbon G3P gets oxidized (loses H+ for P) into Pyruvic acid which can be fermented or go to the krebs cycle
- generates 2 net ATP and 2 NADH
- added phosphates reduced NADH, eventually lost to ATP
- this is an example of substrate level phosphorylation
describe the krebs cycle
pyruvic acid from glycolysis releases a CO2 and adds a CoA to make acetyl CoA
- oxaloacetic acid in krebs cycle takes 2 c groups from acetyl coa and goes through krebs cycle
- produces 4 NADH, 1 FADH2, 1 ATP, and 3 CO2 per pyruvic acid molecule
describe the electron transport chain after the krebs cycle.
uses the energy or electrons from NADH and FADH2 to pump H+ protons against the concentration gradient of membrane
- H goes through ATP synthase and the energy from the proton motor force is used to make ATP
- example of oxidative phosphorylation
- most efficient in making ATP - makes 34 ATP
what were some of the proteins mentioned in the ETC?
- flavoproteins : integral membrane protein that contains derivative of riboflavin
- metal containing proteins like FeS
- ubiquinones - nonprotein carriers found in all cells derived from Vit K
- cytochromes - associated with heme
H’s donated by NADH and FADH2 - NADH donated higher at flavoproteins and can contribute more energy than FADH2 who donates at ubiquinones
what does an electron transport chain require?
requires a membrane that can be used to establish a proton gradient
- inner membrane in mitochondria and cytoplasmic membrane in prok
- used in oxidative and photo phosphorylation.
what are the differences between aerobic and anaerobic respiration?
aerobic respiration - the terminal electron acceptor is O2 which gets reducers into H2O
anaerobic respiration - terminal e- acceptor is not O2 ex. NO3- to NO2-
both can use pyruvic acid after glycolysis
describe the process of fermentation
paertial oxidation of sugar to release energy using organic molecule within cell as the e- acceptor
- low amounts of ATP generated
- regenerates NAD+ by oxidizing NADH so it can be used again in glycolysis
- does not require O2 and does not use Krebs cycle or ETC
- products are determined by the type of organism
describe protein catabolism
proteases - enzymes that break down proteins into amino acids
- AA’s get deaminated (amino group removed) and hydrolyzed (add OH) and can go into the Krebs cycle
- can increase ammonia in body - can be toxic
describe fat catabolism
lipases: enzymes that break drown fats into fatty acid and glycerol using 3 H2O molecules
- glycerol uses ATP to become GP3 that can go into glycolysis
beta oxidation: pairs of C’s get split off from hydrogenated carbon chains of fatty acids
- each pair gets a CoA to become Acetyl CoA and go into krebs cycle
- each pair removed generates an NADH and and FADH2
- occurs in cytosine
describe the pentose phostpate pathway
phosphorylated 5 carbon sugar intermediate formed from glucose
- important formation of products used for anabolic reactions like NADPH for photosynthesis, precursors for nucleotides, AA’s and the calvin cycle
- makes one ATP molecule per glucose
what is the purpose of the light dependent and light independent reactions?
light dependent - chlorophyll captures light energy by exciting electrons
- this generates ATP and NADPH needed for light independent reactions
light independent reactions - fixes CO2 into glucose
describe cyclic and non cyclic photophosrphylation
cyclic - PS1
- light hits chloroplast of PS1, excites e- which goes down ETC
- energy used to pump H+ against proton gradient, used to make ATP through ATP synthase
- e- goes back into PS1 to get reexcited
non cyclic - PSII
- excited e- gets passed to cytochromes, energy used to pump H+ against proton gradient and makes ATP
- e- gets passed down ETC to NADPase, reduces NDAP+ to NADPH for calvin cycle
describe the light independent reactions of photosynthesis
calvin cycle
- uses 6 ATP & 6 NADPH made in dependent rxns
- RuBP: product of pentose phosphate cycle
- RuBP + 3 C’s = 6 C molecule. add the ATP & NADPH to get G3P
- 2 G3P from calvin or glycolysis makes 6 c glucose
what is an amphibolic pathway?
pathways that can proceed in either direction - anabolic or catabolic
- ex. fat catabolism or anabolism
what are some required elements of bacterial growth?
- major element CHONPS
- components of proteins, carbs, lipids, nuclei acids
- trace elements: required in very small amounts (zinc, copper, etc.)
growth factors; organic compounds needed that cannot be synthesized by the microbe
what are the sources of energy for photo vs chemo trophs? what are the carbon source of hetero vs auto trophs?
chemo: energy from chemical compounds
photo: energy from light
auto: carbon from CO2
hetero: carbon from organic compounds
