Cell Structure &functions Lec 10

Question 1

What is TCA?

Answer 1

-After glycolysis, pyruvate can be converted into more energy during aerobic respiration
-Occurs in mitochondria
-Requires oxygen(O2)
-Converts pyruvate into <15 ATP
-A major source of cellular energy

Question 2

Define Pyruvate dehydrogenase

Answer 2

-Is a complex of three enzymes in a mitochondrial matrix
-Transfers two carbons from 3-carbons from 3-C pyruvate to coenzyme A to create a 2-C acetyl-CoA
-Produces CO2 with the third carbon (oxidized)
-Transfers electrons to NADH (reduced)

Question 3

Define Coenzyme A (CoA)

Answer 3

-Is an essential cofactor for the catabolism of carbohydrates,lipids and amino acids
-Transfers two carbons from acetyl groups
-Are involved in electron transfer at multiple metabolic steps

Question 4

Define Acetyl-CoA

Answer 4

-Breaks molecules down two carbons at a time
-Acetyl groups are rich sources of energy
-Acetyl groups have three carbon-hydrogen bonds, which are a source of three electrons
-Alanine can be converted into pyruvate and then acetyl-CoA
What are the three enzymes that are associated with pyruvate?
1)2-oxogulatarate
2)Glutamane
3)alanine

Question 5

Define Lipid droplets

Answer 5

-Can provide metabolites to mitochondria
-Free fatty acids (FA) can be sorted in droplets, which can transfer fatty acids to mitochondria

Question 6

What is Triacylglycerol (TAG)

Answer 6

-Lipid droplets store neutral lipids(TAg and Sterol Esters)in micelles
-The acyl chain of lipids is a great source of energy, and TAG has three acyl chains

Question 7

Define Lipase

Answer 7

-Enzymes catalyzed toward the removal of the three acyl chains from glycerol
-Glycerol can be phosphorylated and enter glycolysis in the cytosol(at step 6) to form pyruvate
-Each acyl chain can be coupled to CoA(Costs and ATP) and transported into the mitochondrial matrix
-Acyl chains are polymers of reduced carbons (full of energy)

Question 8

Define Beta-oxidation

Answer 8

-In mitochondria produces acetyl-CoaA from acyl chains
-For every two carbons in the acyl chain, an acetyl-CoA is produced
-Electrons are also transferred to FADH2 and NAD
-B-Oxidation of the three 14 carbon acy; chains from one TAG molecule results in 21 acetyl-CoA,21 FADH and 21 NADH to produce more energy

Question 9

Define FAD+ vs. FADH2

Answer 9

-Is an unchangeable unculotide that binds with electrons and transferred them within its molecules
-The more carbon hydrogen bonds in a molecule the more energy can be made from its catabolism

Question 10

Define Electron shuttle

Answer 10

-Happens across the mitochondrial members on the molecules
-Electrons transfer from cytosolic NADH to MItochondial FADH2
-The electrons are transferred to other molecules (Glycerol 3p or malate)
-Electrons transfer regenerates NAD+ in the cytosol
-The electrons end up on FAD in the matrix (FADH)
-There needs to be a place where electrons are being handed off to through the
mitochondria and the NAD+
-Electrons have a high energy transfer to the matrix for the electron transport chain
-NAD+needs to be replenished in the cytosol for glycolysis to continue

Question 11

What is the TCA cycle and critic acid or kerbs cycle

Answer 11

–A cell catabolic pathway leads to the TAC cycle and electrons transport chain to power ATP synthesis
-Was created by the nobel precise winner Hans Adolf kerbs who has this award in physiology or medicine in 1953
What is the process of consuming one acetyl coA in the TCA cycle(slide 26)
1)produces 1GTP
2)Transfers electron to 3 NADH,1FADH2
3)Produces 2 CO2
4)Replenishes COA
5)Replenishes Oxaloacetate

Question 12

What substances are consumed in the TCA cycle?

Answer 12

-ATP hydrolysis,ATP is consumed
-Pi and ADP are produced
-In the TCA cycle, acetyl-CoA, NAD+, FAD, GDP, and Pi are consumed
CoA, CO2, NADH, FADH2, and GTP are produced

Question 13

What are the feature of the TCA cycle?

Answer 13

-Small lines are what describes the consumption of the TCA cycle
-Was created by the nobel precise winner Hans Adolf kerbs who has this award in physiology or medicine in 1953

Question 14

Define Circular pathway

Answer 14

-Only external compounds that enter the cycle are consumed and only products that exit the process are produced
-All metabolites in the cycle are replenished

Question 15

What is your main focus in this unit

Answer 15

-High -∆G ̊ reactions fuel downstream reactions
(coupling of exergonic, spontaneous reactions)
-Metabolites in the cycle are replenished, allowing the cycle to run continuously in the mitochondrial matrix

-Acetyl-CoA is oxidized into CO2, transferring electrons to coenzymes NADH and FADH2 for the electron transport chain, and fueling GDP phosphorylation to generate GTP

Question 16

Relative energy output of glucose vs. alanine vs. triacylglycerol

Answer 16

Substrate
1)Glucose-ATP/GTP:4-NADH/FADH:12
2)Alanine- 1-4
3)14-C Triacylglycerol-20-126