Chapter 9 - Cellular Respiration Flashcards
define cellular respiration
the catabolic pathways of aerobic and anaerobic respiration, which break down organic molecules and use an electron transport chain for the production of ATP; the oxidation of glucose and the capture of energy in a useful form
what is the chemical reaction equation for photosynthesis?
6CO2 + 6H2O + light energy -> C6H12O6 + 6O2
what is the chemical reaction equation for cellular respiration
C6H12O6 + 6O2 -> 6CO2 + 6H2O + ATP energy + heat
in what part of plant cells does photosynthesis occur?
chloroplasts
where does cellular respiration occur?
the mitochondria
what two mechanisms generate ATP?
substrate-level phosphorylation and oxidative phosphorylation
define oxidative phosphorylation
energy is stored as a hydrogen ion gradient across a membrane, then used to make ATP
define substrate-level phosphorylation
enzyme transfers phosphate group from organic substrate to ADP
describe glycolysis
glucose -> pyruvate - (in the cytosol)
describe breakdown of pyruvate
formation of acetyl-CoA (in matrix) and citric acid cycle (Krebs cycle) (in matrix) - (in mitochondrion)
describe oxidative phosphorylation
- electron transport chain (in inner membrane) 2. ATP synthesis (by chemiosmosis) - (in mitochondrion)
describe fermentation
a. lactic acid fermentation b. alcohol fermentation - (in cytosol)
list the processes involved in cellular respiration
redox reactions, chemiosmosis, phosphorylation
what is glucose a rich source of and what withdraws it from glucose?
glucose is a rich source of electrons, NAD+ and dehydrogenase withdraw these electrons
describe the electron transport chain
electrons cascade down series of electron carriers of the electron transport chain; in cellular respiration, cascading electrons release energy in small increments and finally reduce O2
define glycolysis
harvesting chemical energy by oxidizing glucose to pyruvate; takes place in the cytosol; begins the oxidation of glucose; nets 2 ATP and 2 NADH
what two phases can glycolysis be divided into?
the energy investment phase and the energy payoff phase
is O2 needed in any of the glycolytic reactions?
no. no O2 is needed in any of the glycolytic reactions
what is formation of Acetyl-CoA?
pyruvate is groomed for the citric acid cycle
where does the Krebs cycle occur?
in the mitochondrial matrix
what does the Krebs cycle do?
completes the oxidation of organic fuel
what does the Krebs cycle produce?
ATP, NADH, FADH2, CO2
what does the electron transport system do?
built into the inner mitochondrial membrane, electrons lose energy as they are passed along, energy is used to pump hydrogen ions against the gradient into the intermembrane space
what donates electrons to the electron transport chain?
NADH and FADH2
what is the most common control mechanism?
feedback inhibition
when does fermentation occur?
after glycolysis when there is no oxygen available
what is the purpose of fermentation?
an anaerobic alternative to aerobic respiration
list examples of alcohol fermentation
by yeast in brewing, winemaking, and baking
what fermentation do human muscle cells use?
lactic acid fermentation to generate ATP when O2 is scarce
