metabolism
the sum total of chemical reactions of biosynthesis
Anabolism
-build up
-smaller molecules
-often requires energy
catabolism
-break down
-large to smaller
-often releases energy
coenzymes that act as electrons carry
a hydrogen
ATP
-powerhouse molecule, high energy host
-ADP and ATP
ATP can be generated by
-substrate-level
-oxidative phosphorylation
substrate level
phosphate is transferred from a phosphorylated compound directly to ADP
oxidative phosphate
a series of redox reactions that occurs during electron transport
nutrient acquisition eukaryotic cells
-macromolecules taken in by endocytosis
-digested in the lysosome or phagolysosome
nutrient acquisition prokaryotic cells
-no endocytosis not able to ingest large molecules
-secrete digestive enzymes and take in smaller molecules by active transport
-some are unable to produce hydrolyses and rely of prokaryotic
three main metabolic
aerobes, anaerobes, facultative anaerobes, all three start with glycolysis
aerobes:
use aerobic respiration
anaerobes
use anaerobic respiration or fermentation
facultative anaerobes
-use aerobic respiration anaerobic respiration or fermentation
monosaccharides
-single sugars
disaccharides
-2 monosaccharides
a bacterium may be unable to utilize a particular sugar because
it does not synthesize the appropriate
it does not possess the appropriate transport protein in its membrane
glycolysis
-first pathway in metabolism
-Location: cytoplasm of pro and eu
2 main types of glycolysis
-Embden- EMP pathway
-ED pathway
EMP pathway
-classic glycolysis used by many bacteria and eukaryotic cells
-this is the glycolysis pathway described in you book
-conversion of 6C glucose into two molecules of 3-C pyruvate
-generates ATP via substrate-level
-generate NADH
-spends some ATP
EMP 1st half
-first part requires energy
-6 carbon split into 2 three carbon sugars
EMP 2nd half
-each carbon sugar is converted, through several steps to pyruvate,
-ATP is provided by substrate level phosphorylation
-2 NADHS produced
-4 ATPS are produced
-via substrate level
products glycolysis
-2 atps used in the first half
-4 atps produced in second half
-2 NADHS produced in second half
-two water molecules produced in second half
Net gain from EMP pathway
-2 ATP
-2 NADH that will go into the electron transport chain
-2 h20
-2 pyruvate-which continue into krebs or fermentation pathways
Products of ED Pathway
-1 ATP first half
-1 NADH produced in first half
-1 water molecule produced in first half
-2 atps produced in second half
-1 NADH produced in second half
ED pathway net yield
-1 atp
-1 NADH-will go to electron transport chain
-1 NADH
-1 H2O
-2 pyruvate
What all glycolytic pathways have
-all start with a sugar, usually glucose
Krebs cycle
-used in aerobic and anaerobic respiration
-purpose is to oxidize pyruvate
-electrons are transferred from NAD and FAD and add a H
-location: cytoplasm of eukaryotes
products of krebs per spin:
-4 NADH
-1 FADH
-1 ATP
-3 co2, 1 h2o
products krebs per glucose
-8 NADH
-2 FADH
-2 ATP
will go into the electron transport chain
Electron transport chain
purpose: to use the electrons carried by NADH and FADH to generate ATP
-Location: cytoplasm in por, mictochondia for eukaryotes
-used by aerobes and anaerobes
ATP yeild ETS per NADH
-aerobic yields 3 atps
-2 NADH from glycolysis
-8 NADH from krebs
-30 atp
ATP yield per 2 ATP FADH
-2 fADH
-4 ATPS
Oxidase Test
-test for cytochrome c oxidase
-turn purple
anaerobic respiration
-used by anaerobes and some facultative anaerobes
-anaerobic respiration is less efficient
Why do facultative aerobes preferentially respire aerobicall when oxygen is available?
-Aerobic respiration is more efficient, producing far more ATP via oxidative phosphorylation than by anaerobic pathways
catalase test
-decompose co2
-will bubble