MCB-150 Study Set: Cellular Respiration Terms & Definitions

Cellular Respiration is the break down of _____ to _______

glucose --> CO2 & H2O

Glycolysis (purpose, what it starts & ends with)

-Phase 1 of making ATP from glucose (cellular respiration)

-Glyco(sugar) + lysis(break)

-Starts with 6-carbon sugar (glucose), ends with twp 3-carbon molecules (pyruvate)

Where does glycolysis occur? (eukaryote and prokaryote)

Cytoplasm of all living cells

How many steps in glycolysis, and which are endo/exer?

5 total steps:

2 steps endergonic

3 steps exergonic

What are the problems remaining at the end of glycolysis? (3)

1. molecules not at lowest energy state

2. some energy is being help ad NADH

3. NAD+ is being used up and not replaced

Aerobic Respiration

-carbon source (2 molecules pyruvate) converted to CO2 (pyruvate -> acetyl coA -> Krevs cycle)

-6 CO2 released

-Energy transferred to NAD+ & FAD

-another SLP reaction in krebs cycle (GTP is ATP analog)

Anaerobic respiration

-carbon source (2 molecules pyruvate) converted to CO2 (pyruvate -> acetyl coA -> Krevs cycle)

-6 CO2 released

-Energy transferredto NAD+ & FAD

Fermentation-

-occurs after glycolysis, no (2 and no terminal elector acceptor

Where does aerobic respiration occur? (euk and prok)

Eukaryotes: Cytoplasm

Prokaryotes: Plasma membrane

WHat occurs after glycolysis if O2 is present?

aerobic respiration

What occurs after glycolysis if O2 is not present but terminal electron accept exists?

anaerobic respiration

What occurs after glycolysis if O2 is not present and no terminal electron accept exists?

Fermentation

WHy is Krebs cycle dependent on oxygen?

-aerobic respirations requires O2, krebs cycle itself doesnt

-krebs cycle is coupled to third pathaway which requires oxygen (electron transport chain)

Electron Transport Chain

-NADH passes its electrons (and is reoxidized to NAD+) to first carrier

-1st electron carrier passes to 2nd, 2nd to 3rd, etc (diff. in energy is released when electrons are passed)

-that energy is used to pump protons across membrane (proton/electrochemical gradient produced)

Proton/Electrochemical gradient

-pumps protons across membrane

-uses energy from diff in energy as carriers are passed in electron transport chain

Cayonase

group(family) of enzymes that adds phosphate groups onto other molecules (phosphorylates other molecules)

Phosphatase

removes a phosphate group from a molecule

Allosteric regulations (AR)

-AR molecules binds to binding site other than active site

-change conformation of active aite

-either up(positive regulator) or down(negative regulator) activity of enzyme

-positive regulator if up enzyme activity, negative if down

Feedback Inhibition

How many ATP made because of cellular respiration?

36

Path of C and H in glucose Phase 1-3

GLycolysis: 1 glucose to 2 pyruvate

Krebs cycle: carbons released as CO2

ETC and Oxidative Phosphorlyation: Hydrogens combine with O2 to form H2O

What happens to aerobically-respiring cells under anaerobic conditions?

-perform glyoclysis but no Krebs ETC or OP so ALL ATYP COMES FROM GLYCOLYSIS

-pyruvate goes and fermentation (no additional ATP but faster rate)