cell metab

Home > Preview

The flashcards below were created by user lintyone on FreezingBlue Flashcards.

anabolism

sum of synthesis rxns
why do cells synthesize new organic molecules?
- cell growth
- maintenance
- repair
- synthesis of energy reserves (glycogen, proteins)
smaller mol --> larger mol reqs E
catabolism

sum of all decompostion rxns
catabolism
PDTs go into nutrient pool for:
- anabolism- making new mol
- further catab in mitochondria
- 40% ATP synthesis
- 60% lost as heat
larger mol to smaller mol - produces E
ATP
nucleotide + 1 or 2 Pi = Stored E

Hydrolysis of terminal phosphate of ATP releases ~7.3 kcal/mol of E

ATP --> ADP + Pi + E

majority of ATP is from mitochondria
mitochondria
- membranous organelle producing ATP
- "powerplant of cell"
- one, none or several per cell
- liver & muscle cells have multiple
mitochondria makeup
- outer membrane
- inner membrane
- matrix
mitochondria makeup
outer membrane

separates mitochondria from cytoplasm
mitochondria makeup
inner membrane
- folds (cristae) increase surface area
- increases ATP production
- location of ETC
- ETC = oxidative phos. & a lot ATP productn
mitochondria makeup
matrix
- "liquid" inside inner membrane
- location of TCA cycle (Krebs cycle)
metabolism

all chemical rxns occuring in organism

metab = anab + catab

glycolysis & TCA are center of cell metab
preferred energy sources of cell metab
- glucose
- triglycerides
- proteins
preferred energy sources
glucose
- *preferred E source
- source: diet & glycogen stores (liver)
glycogen --> glucose
- - brain uses under non-starve condtns
- - only fuel that RBCs use
preferred energy sources
triglycerides
- 2nd fave E source
- TG --> F.A + glycerol
- source: diet & triglyceride stores (adipocytes)
preferred energy sources
proteins
- 3rd fave
- Protein --> aa
- source: diet & protein stores (muscle)
- only used under duress
carb metab
cellular respiration
- use of O₂ to convert organic mol into CO₂ & H₂O
- (by removing e^-) to create E
- C₆H₁₂O₆ + 6O₂ -->
- 6CO₂ + 6H₂O + Energy
processes involved in cellular respiration
- glycolysis (can occur in anaerobic condtn)
- TCA Prep (need O₂)
- TCA cycle (need O2)
- ETC (need O2)
Coenzymes: NAD⁺& FAD
- non-protein, organic mol; usually vitamins
- carry H atoms, released during cell resp
- NADH & FADH₂ both take 2 H off whoever
- The 2H reduce NAD⁺ & FAD = NADH & FADH₂
- FAD can carry 2e & 2H = FADH₂
- NAD⁺ can carry 2e & 1H
NAD
B3 Niacin
- nicotinamide
- adenine
- dinucleotide
FAD
B2 Riboflavin
- Flavin
- Adenine
- Dinucleotide
Glycolysis
- [location: cytoplasm]
- glu in via carrier proteins (passive!)
- phosphorylated --> glucose-6-phosphate
- ATP -> ADP = fructose-1,6-bisphosphate
- 6C convert to 2-3C
- (glyceraldehyde-3-phos & dihydroxyacetone phos)
- 2NAD -> 2NADH (1,3-bisphosphoglyceric acid)
- 2ADP -> 2ATP (3-phosphoglyceric acid)
- release 2H₂O
- Phosphoenolpyruvic acid
- 2ADP - 2ATP --> pyruvic acid
Glycolysis
- 1 glucose converted to 2 pyruvate
- PDTS = 2ATP & 2NADH
2NADH transported into mitochondria for ETC

2Pyruvate then enters mitochondria (passive, no ATP)

*O₂needed to continue, bc O₂ needed to regenerate NAD⁺
TCA Prep
aka oxidative decarboxylation of pyruvate
- pyruvate in mitochondrial matrix
- O₂ needed!
- C & O₂ removed (=CO₂)
- H removed & added to NAD⁺ (=2NADH)
- Results: 2 acetyl grps combine w/CoA
- =>2 Acetyl CoA
- PDTS: 2CO₂ & 2NADH
TCA Cycle: Overview
- [occurs in mitochondrial matrix]
- -each (2) acetyl CoA enters cycle
- -2 cycles/glucose mol
- -acetyl grp + oxaloacetic acid (4C)
- => citric acid (6C)
- -Citric Acid oxidized (H to NAD⁺ or FAD)
- carbons removed (CO₂ generated)
- Regenerate oxaloacetic acid (4C)
- **cycle goes around 2x!
Products of TCA cycle
- 4 CO₂
- 6 NADH
- 2 FADH₂
- 2 ATP from GTP
How is ATP made?
- ADP + Pi --> ATP
- phosphorylation
2 types of phosphorylation make ATP
- substrate level phosphorylation
- oxidative phosphorylation
substrate level phosphorylation
- reactive intermediate
- (GTP & 1,3-bisphosphoglyceric acid & phosphoenolpyruvate in glycolysis)
- E needed to make ATP comes from breaking GTP
- GTP -> GDP +Pi
- Pi + ADP -->(via nucleoside diphosphate kinase) ATP
oxidative phosphorylation

E needed to make ATP from transfer of e (oxidation) in ETC via ATP Synthase (complex 5 in ETC)
Which type of phosphorylation rxn makes more ATP?

oxidative phosphorylation
oxidation & phosphorylation coupled to make lots of ATP
- glucose donates H atoms to carrier mol (NAD FAD), NAD, FAD oxidized (donate H atoms) in ETC.
- ETC enables phos. of ADP --> ATP
oxidation
- NADH + FADH2 oxidized
- => NAD+ & FAD in ETC
phosphorylation
- ADP + Pi converted via ATP Synthase
- => ATP
- 2 H₂ + O₂ --> 2 H₂O + energy
- highly exergonic rxn
- must be dispersed over series of small controlled steps in ETC
ETC - overview
10 NADH & 2FADH₂ accumulated
- Hydrogen Atom
- e- enter ETC
- proton pumped into intermembrane space
ETC produces >90% of all ATP
ETC: Oxidation-Reduction Rxns
Location?

mitochondrial inner membrane
ETC: Oxidation-Reduction Rxns
What happens to NADH & FADH₂?
- becomes oxidized (NAD⁺ & FAD) when transferring e- to proteins of ETC
- transfer of e' reduces these proteins of ETC
- as proteins in chain r reduced/energized some can pump H ions into intermem.space
- oxygen is final e' acceptor. Gradual process
- Oxygen +2H = H₂O
What are the proteins of the ETC?
- Coenzymes
- Cytochromes
What do coenzymes do?
- accept H atoms (& become reduced) from NADH & FADH₂
- made up of: complex I, II, coenzyme Q
Coenzymes
Complex I
- receives 2H atoms from NADH
- Transfers 2e to Coenzyme Q & pumps 2H into intermembrane space
- (2H= 1 from NADH, 1 from matrix)
Coenzymes
Complex II
- receives 2H atoms from FADH₂
- transfers 2e to Co.Q & 2H released (not pumped)
- (FADH₂ goes along w/ComplexII)
Coenzymes
Coenzyme Q
- receives e- from Complex I & Complex II
- passes them to cytochromes

Card Set Information

Author:	lintyone
ID:	104340
Filename:	cell metab
Updated:	2011-09-26 13:58:13
Tags:	ibhs2b
Folders:
Description:	IBHS.E2.L2.Nickola
Show Answers: