Chapter 7: Energy and Cell Respiration Flashcards
The need for energy in living organisms
Why is Carbon a vital element?
for living organisms
All macromolecules are made of Carbon
-> Requires Carbon to synthesize
The need for energy in living organisms
What are organisms that use inorganic carbon source called?
CO2, synthesizing their own organic molecules
Autotrophs
like plants
The need for energy in living organisms
What are organisms that use organic Carbon supply called?
ready-made organic supply of C
Heterotrophs
like animals
The need for energy in living organisms
Relationship between autotrophs and heterotrophs?
Heterotrophs depend on autotrophs
‘cause they can’t make their own organic supply
The need for energy in living organisms
2 uses of organic molecules in living organisms?
related to catabolism and anabolism
- Anabolism: building blocks to form macromolecules
- Catabolism: store chemical potential energy in bonds
break the bonds for energy
Work that cells do
What is work?
- Energy consumption
- Energy in transition between states/objects
Work that cells do
Some types of doing work in living organisms?
just name a few
- synthesis of macromolecules
- active transport (pumps)
- muscle contraction
- bioluminescence
- cellular movements
Work that cells do
What process of what substance gives energy for cells to do work?
Oxidation of glucose
Work that cells do
Equation for oxidation of glucose?
C6H12O6 + O2 -> 6 CO2 + 6 H2O + 2870 kJ
exergonic (energy of product < energy of reactant => released energy)
Work that cells do
Why won’t cells simply burn glucose but need respiration?
Too much energy released at once:
* wasted
* harm cells
Work that cells do
Why must cells convert energy into ATP?
adenosine triphosphate
Store energy for later use
energy currency of cells
ATP
How is energy extracted from ATP?
Removes phosphate group 1 by 1
dephosphorylate
ATP
Dephosphorylation of the 1st and 2nd phosphate group gives 30.5 kJ/mol, but the 3rd only gives 14.2 kJ/mol. Why?
Link between γ-β and β-α phosphate group is phosphoanhydride, while α-ribose is phosphodiester
Energy of phosphoanhydride > phosphodiester
ATP - Synthesis of ATP
How?
- Using energy released by chemical reaction to phosphorylate ADP (substrate-linked reaction)
- Movement of H+ down a concentration gradient (chemiosmosis)
glycolysis, Krebs cycle and oxidative phosphorylation
ATP - Synthesis of ATP
Which method is more used by a cell to create ATP?
substrate-linked-reaction or chemiosmosis
Chemiosmosis
