chapter 7 - cellular respiration and fermentation

autotroph

an organism able to produce its own organic molecules through photosynthesis

heterotroph

an organisms able to live on organic compounds produced by other organisms

cellular respiration

the process by which energy is harvested from organic molecules

oxidation reactions

reactions that break the high energy C—H bonds in organic molecules

redox (oxidation-reduction) reactions

chemical reactions where electrons are transferred from one molecule to another

reducing agents

molecules that can donate electrons

oxidizing agents

molecules that can accept electrons

molecules that ___ electrons after the reaction are ___, and those that ___ electrons are ___

gain, reduced; lose, oxidized

dehydrogenation

lost electrons are accompanied by protons

electron carriers

molecules in cellular respiration and photosynthesis that shuttle electrons to ETC

NAD+

an electron carrier that accepts 2 electrons and 1 proton to become NADH+

dephosphorylation

the loss of a phosphate group from a molecule

phosphorylation

the addition of a phosphate group

substrate-level phosphorylation

an enzyme transfers a phosphate directly to ADP, occurs in cytosol, does NOT need oxygen

oxidative phosphorylation

associated with electrons “falling” toward oxygen in ETC, occurs in mitochondria, NEEDS oxygen

cellular respiration equation

C6H12O6 + 6 O2 → 6 CO2 + 6 H2O

glucose is ___ to carbon dioxide

oxidized

oxygen is ___ to water

reduced

oxidation of glucose

1. glycolysis

2. pyruvate oxidation

3. citric acid cycle

4. ETC and chemiosmosis 

products of glycolysis

2 NADH, 2 ATP

products of pyruvate oxidation

2 CO2, 2 NADH

products of citric acid cycle

4 CO2, 2 FADH2, 6 NADH, 2 ATP

products of ETC and chemiosmosis

28 ATP

total products of the oxidation of glucose

6 CO2. 2 FADH2. 10 NADH, 32 ATP

ATP yield

30-36 glucose, stores ~34% of energy

anaerobic respiration

use of inorganic molecules (other than O2) as final electron acceptor, occurs when oxygen is not present

fermentation

reduces organic molecules to regenerate NAD+

lactic acid fermentation

electrons are transferred from NADH to pyruvate to produce lactic acid, occurs in animal cells (muscles) and bacteria, lactate is final electron acceptor

ethanol fermentation

produces CO2, ethanol, and NAD+, occurs in yeast, ethanol is final electron acceptor