Module 3 Flashcards

Question

how is energy stored in fats?

Answer 1

it is stored as triacylgylcerols throughout the body but it must be broken down to release free fatty acids that need to be transported into the cells that need energy production

Answer 2

it is stored mainly as skeletal muscles and is only used in extended fasting periods

Answer 3

1. monosaccharides - most commonly consumed in the form of glucose 2. disaccharides - consists of two monosaccharides bonded by an alpha or beta 1-4 glycosidic linkage (lactose = galactose + glucose) 3. polysaccharides - much long chains of monosaccharides (glycogen which is a storage molecules that must be broken down before it can be used to produce energy)

Answer 4

glucose enters the bloodstream from ingested food though de novo synthesis (formation of complex molecules in the body from simple molecules) in the body or from the breakdown of glycogen stores. once in the blood glucose circulates and is available for use. to get glucose into cells, glucose transporters are used

Answer 5

1. it is the break down of glucose and the transfer of the energy produced to high energy electron carriers and ATP 2. catabolic reactions are exothermic so a series of steps must occur as glucose has a lot of energy stored so it all the energy was released at the same time there would be lots of heat which would likely kill the cell 3. multiple steps allows monosaccharides to enter glycolysis (do not have the same yield as glucose)

Answer 6

1. one glucose molecule is converted into two glyceraldehyde 3 phosphate (G3P) molecules in the first five reactions, this required two ATP 2. each G3P molecule enters the sixth and seventh reactions and is converted into 3 phospholglycerate (for each G3P 1 ATP and 1 NADH is produced) 3. each 3 phosphoglycerate produces 1 pyruvate and 1 ATP (net of 2 ATP, 2 pyruvate and 2 NADH produced)

Answer 7

if it were to build up to a sufficient concentration it is possible the conversion of glucose would stop and discontinue ATP production, to prevent this pyruvate is further processed. (dependent if oxygen is present)

Answer 8

it occurs when there is an absence of oxygen in the cytoplasm. pyruvate undergoes fermentation so NADH can be oxidized to NAD+ (regenerated so glycolysis can reuse). produces one of two products 1. animal cells and bacteria - pyruvate is reduced to lactate 2. plant cells and yeast - pyruvate reduced to ethanol

Answer 9

occurs in the presence of oxygen in the mitochondria 1. conversion of pyruvate to acetyl CoA 2. krebs cycle 3. the electron transport chain 4. chemiosmotic gradient 5. formation of ATP by ATP synthase

Answer 10

1. pyruvate in the cytosol is transported into the mitochondria 2. carrier molecules on the inner mitochondrial membrane brings pyruvate into the matrix 3. in the matrix pyruvate is decarboxylated by the pyruvate dehydrogenase complex 4. the complex takes pyruvate, an NAD+ and a CoA molecule and converts them into acetyl CoA, NADH and CO2 (note - one glucose yields two pyruvate so net energy production at this stage is 2 NADH)

Answer 11

1. acetyl CoA enters the cycle by combining with oxaloacetate to form citrate (6 carbon molecule) 2. CoA is released (can be reused) 3. citrate is broken down by several reactions to remove two of the carbons to create succinate 4. the release of carbons transfer energy to two NAD+ to form two NADH, and are released in the form of two CO2 and one GTP (like ATP) 5. succinate is converted back to oxaloacetate which released one NADH and one FADH2

Answer 12

each acetyl CoA produces 3 NADH, 1 FADH2 and 1 GTP (ATP) so the the net is 6 NADH, 2FADH2 and 2 GTP (ATP)

Answer 13

4 ATP, 10 NADH and 2FADH2 in total however 2 of the NADH are in the cytosol not the mitochondria. glycerol phosphate shuttle is a mechanism in the mitochondria that uses cytosolic NADH to produce FADH2, so in the mitochondria the total would then be 8 NADH, 4 FADH2 and 4 ATP

Answer 14

it is the process used by the mitochondria to converts NADH and FADH2 into ATP. it refers to the ETC, the chemiosmotic gradient that it creates and the activity of ATP synthase

Answer 15

it is a collection of protein complexes (four) and electron carriers found within the mitochondrial inner membrane. the purpose of the ETC is to use the energy of the energy carriers (NADH and FADH2) to pump protons into the inter membrane space (note - NADH and FADH2 enter the ETC at different points, NADH enters first and moves more protons so generates more ATP). process also combines oxygen and protons to produce water

Answer 16

complex I - NADH coenzyme Q oxidoreductase uses electron from NADH to pump protons from the matrix to the inter membrane space

Answer 17

complex II - succinate coenzyme Q oxidoreducatse passes electrons from FADH2 to the ETC releasing protons into the matrix

Answer 18

coenzme Q cytochrome c oxidoreducatse uses electrons from both NADH and FADH2 to pump protons from the matrix to the intermembrane space

Answer 19

complex IV 0 cytochrom c oxidase uses electrons from complex III to pump protons from the matrix to the inter membrane space

Answer 20

it is a proton gradient created across the inner mitochondrial membrane during ETC. protons are in high concentration to allow ATP synthase to generate ATP

Answer 21

ATP synthase is located within the inner membrane and uses the established proton gradient to phosphorylate ADP into ATP (chemiosomotic reaction). this occurs after protons have been pumped into the mitochondria via the ETC and ions are moved down their concentration gradient

Answer 22

1. NADH produces up to 3 but realistically 2.5 2. FADH2 produces up to 2 but realistically 1.5

Answer 23

ATP is not very stable and there is no direct storage so creatine kinases converts creatine and ATP to create creatine phosphate and ADP. when ATP demand is high a reverse reaction occurs which does not need oxygen

Answer 24

it occurs in the mitochondria however fatty acids cant cross the membrane without help. fatty acid circulating the bloodstream called free fatty acids (FFA) are taken up into cells by a family of fatty acid transport proteins. once inside the cytosol they need to be activated in oder to be transported which is done by 2 ATP per FFA. in the mitochondria fatty acyl CoAs are metabolized by beta oxidation to produce high energy molecules (forms fatty acyl CoA ester) (note - if the tail is short enough it can diffuse into the matrix, if long must be transported by a process called carnitine shuttle)

Answer 25

it breaks down fatty acids two carbons at a time to release acetyl CoA, each cycle releases energy in the form of 1 FADH2 and 1 NADH. to calculate net yield - (beta oxidation + krebs cycle - FFA activation)

Answer 26

nitrogen is removed by deamination and converted into a urea group and excreted in the urine as it cant be used to generate ATP. depending on the amino acid it can result in: 1. three carbon molecules used to synthesize glucose or enter glycolysis 2. formation of acetyl CoA 3. products that can enter as intermediaries of the krebs cycle

Answer 27

primary source is glucose but also get energy from ketones which are produced from the metabolism of fats in the liver

Answer 28

they are composed of a carbonyl group bonded with two hydrocarbon groups that are taken up by neurons and converted into acetyl CoA

Answer 29

primary source is fatty acids although ketones can be used. (operates exclusively on aerobic respiration)

Answer 30

major sources are glucose, fatty acids (used primarily in resting muscles) and ketones. they have large stored of glycogen. heavy exercise leads to excess lactate which is excreted and may be converted back to glucose in the liver

Answer 31

1. low - stored fats as long as there is sufficient oxygen 2. medium - stored carbohydrates or glycogen (converted to glucose) 3. high - dependent on muscle glycogen, creatine phosphate used and proteins are used if all other options are used

Module 3 Flashcards

(55 cards)