anaerobic respiration

Question 1

glycolysis

Answer 1

first stage of respiration
-6C glucose split by series of ten reactions into 2 molecules of 3C compound pyruvate

Question 2

pyruvate ions

Answer 2

produced by glycolysis
-can be used in aerobic respiration or anaerobic

Question 3

where does glycolysis take place

Answer 3

in the cytoplasm of the cell

Question 4

what type of sugar is glucose

Answer 4

6C

Question 5

source of glucose for glycolysis

Answer 5

-come directly from blood or produced by breakdown of glycogen stores in muscle and liver cells

Question 6

first step of glycolysis

Answer 6

used ATP to provide energy to phosphorylate the 6C adding two phosphate groups

Question 7

what does the phosphorylation do to the 6C

Answer 7

makes sugar more reactive and makes it unable to pass through cell membrane- trapped in cell

Question 8

step 2 of glycolysis

Answer 8

phosphorylated sugar then split to give two molecules of 3 C

Question 9

whats is split 6C- 3C also known as

Answer 9

-glycerate 3-phosphate GP

Question 10

what then happens to GP

Answer 10

-converted by several steps into molecule of pyruvic acid-found in solution of pyruvate ions

Question 11

step 1 of how ATP produced from glycolysis

Answer 11

-2 hydrogen atoms removed from 3C and taken up by NAS forming reduced NADH
-takes place in cytoplasm
-reduced NADH passes through outer mitochondria membrane into electron transport chain

Question 12

step 2- how ATP made

Answer 12

-small amount of ATP made directly from energy transfer when 3C sugar converted to pyruvate
-phosphorylation of sugar at beginning of glycolysis reversed when final intermediate compound converted to pyruvate
-phosphate group releases used to convert ADP to ATP

Question 13

anaerobic respiration in cytoplasm

Answer 13

if lots of oxygen pyruvate will enter mitochondria and used in aerobic reactions of krebs cycle
-if oxygen levels low pyruvate remains in cytoplasm and converted to ethanol in plants or lactate in mammals
-only little ATP prpduced

Question 14

production place aerobic vs anaerobic

Answer 14

aerobic in mitochondria and anaerobic in cytoplasm

Question 15

oxidation state aerobic vs anaerobic

Answer 15

aerobic complete oxidation and anaerobic incomplete oxidation

Question 16

waste products aerobic vs anaerobic

Answer 16

aerobic- water and carbon dioxide
-anaerobic- lactic acid or ethanol and carbon dioxide

Question 17

net energy aerobic vs anaerobic

Answer 17

-aerobic- 31 ATP
-anaerobic- 2 ATP

Question 18

why do muscles respire anaerobically

Answer 18

-if you exercise hard or long exercises- muscles dont get enough oxygen to supply their needs
-the products pf glycolysis cannot go to krebs cycle so respire without oxygen

Question 19

what happens to pyruvate from glycolysis in anaerobic respiration

Answer 19

-another 3C dissociates to form lactate and hydrogen ions

Question 20

result of anaerobic respiration

Answer 20

only two molecules of ATP are produced per glucose molecule respired
-in contrast- up to 8 ATP molecules are produced in glycolysis when pyruvate can feed into krebs cycle

Question 21

cause of low yield of ATP in anaerobic respiration

Answer 21

-because some of reduced NAD used to reduce pyruvate to lactate rather than entering electron transport chain

Question 22

lactate moving out of cells into blood equation

Answer 22

glucose to lactic acid + ATP
-C6H12O6 TO 2C3H6O3

Question 23

how do muscle tissues become acidic

Answer 23

as levels of lactate and hydrogen ions increase during anaerobic respiration in muscles pH falls and becomes acidic

Question 24

real reason for muscle tissue becoming acidic

Answer 24

neither lactate ions or fall of pH affect muscle contraction
-movement of lactate and hydrogen ions into blood from muscles lowers pH of blood- affects CNS
-reduced nervous stimulation from CNS reduces muscle contraction
-protective adaptation to give muscles time to recover and return to aerobic to raise pH of blood

Question 25

what happens when exercise stops

Answer 25

levels of lactate remain high in blood
-lactate= toxic
-must be oxidised back to pyruvate to enter krevs cycle to be respired with oxygen
-takes oxygen to oxidise accumulated lactate

Question 26

how training helps athletes

Answer 26

-allows the to get more oxygen to muscles faster as better blood supply develops
-helps to tolerate higher levels of lactate before muscles fatigue

Question 27

what happens with repeated exposure to high lactate levels

Answer 27

-more lactate transporter molecules develop in the mitochondrial membranes resulting in faster processing of lactate to pyruvate when oxygen available

Question 28

part where plants undergo anaerobic respiration

Answer 28

root cells in waterlogged soils

Question 29

equation for plants producing yeast

Answer 29

glucose= ethanol + carbon dioxide
-ethanol= C2H5OH + 2CO2

Question 30

main experimental organism used in work on glycolysis

Answer 30

-yeast rather than plants
-easy to grow
-reproduces rapidly
-no ethical issues
-yeast contains all enzymes of glycolysis

Question 31

stage 1 of workout out glycolysis

Answer 31

-1897- eduard buchner- discovered extract of yeast that has no cells could still convert glucose to ethanol
-showed that enzymes of glycolysis and fermentation are not with associated with structure of cell

Question 32

stage 2 of workout out glycolysis

Answer 32

-early 1900- arthur harden and W.J young showed phosphate was needed for pathway to proceed and there were 2 elements of yeast extract needed before fermentation could go ahead
-one was inactivated by heat as it contained enzymes
-other was not affected by heat in same way and contained NAD- ADP- ATP

Question 33

stage 3 working out glycolysis

Answer 33

-with work of inhibitors allowed some of pathway intermediated to be studied
-Gustav Embden and Otto Meyerhof, received novel prize for work on glycolysis and lactate on muscles
-Jakub Parnas discovering phosphorlysis key

Question 34

alternative names for glycolysis

Answer 34

-embden- meyerhof pathway and embden- meyerhof- parnas pathway