Biology - Respiration Flashcards
What is respiration?
the utilization of oxygen
what is external respiration?
entrance of air into lungs & gas exchange between alveoli and blood
what is internal respiration?
exchange of gas between the blood and the cells
how are photosynthesis and respiration related?
photosynthesis converts sunlight into chemical energy; respiration converts this chemical energy into energy needed for living cell processes
what type of bond can release the most amount of energy?
C-H bond
what is the stable product of respiration? (little available energy)
CO2
is dehydrogenation oxidizing or reducing?
oxidizing
when oxygen accepts the hydrogen, this is…. oxidizing or reducing?
reducing
why is the electron transport chain beneficial in terms of energy production?
it allows for more energy to be harnessed
name the two stages of glucose catabolism
glycolysis and cellular respiration
what 3 things happen in glycolysis?
glucose is broken into 2 molecules of pyruvate; ATP is produced; NAD+ is reduced to NADH
where does glycolysis take place?
cytoplasm
how many molecules of glyceraldehyde 3-phosphate are made from each molecule of glucose?
2
how many ATP are used to make 2 molecules of pyruvate? how many are produced?
2 are used and 4 are produced (so the net = 2)
why is glycolysis considered a substrate-level phosphorylation?
ATP is made directly coupled with glycolysis without the use of intermediate molecule like NAD+
how many NADH are made from one molecule of glucose in glycolysis?
2 (one from each PGAL)
what two ways can the energy stored in pyruvate be accessed?
aerobic respiration (cellular respiration where it is oxidized) or anaerobic respiration (fermentation where it is reduced)
what must be generated for pyruvate to continue without O2?
NAD+
how is NAD+ regenerated?
pyruvate is reduced into ethanol or lactic acid
how many ATP are made from one glucose molecule in fermentation?
2
two organisms that use alcohol fermentation?
yeast and bacteria
summarize alcohol fermentation
pyruvate is converted to ethanol, NAD+ is regenerated and glycolysis is able to continue
where does lactic acid fermentation take place?
fungi, bacteria, human muscles
what happens to pyruvate in lactic acid fermentation?
reduced to lactic acid
how many ATP are yielded in cellular (aerobic) respiration?
36-38
what is the final electron accepter in cellular respiration?
oxygen
where does aerobic respiration take place?
mitochondria of eukaryotes
3 stages of cellular respiration:
pyruvate decarboxylation, citric acid cycle, electron transport chain
what happens in pyruvate decarboxylation?
pyruvate from glycolysis is transported into mitochondria where it loses a CO2 group and the acetyl group is transferred to form acetyl CoA.
when is acetyl CoA formed?
pyruvate decarboxylation
what happens to NAD+ in pyruvate decarboxylation?
it is reduced to NADH
when does citric acid cycle start?
when acetyl group of acetyl CoA combine with oxaloacetate….. 6 carbon citrate forms
how many CO2 molecules are produced in citric acid cycle?
4
how many ATP, NADH and FADH2 are made in the citric acid cycle?
2 ATP; 6 NADH; 2 FADH2
where is the ETC located?
inner mitochondrial membrane
is the ETC substrate-level or oxidative phosphorylation?
oxidative phosphorylation
each carrier in the ETC is reduced when what happens?
as it accepts an electron
how many ATP are made in one turn of the citric acid cycle?
1
total number of ATP made from substrate-level phosphorylation?
4 ATP (2 from glycolysis, 2 from citric acid cycle)
how many ATP does one NADH molecule make?
3
how many ATP does one FADH2 molecule make?
2
how many ATP are made from oxidative phosphorylation?
32 ATP
when are 38 ATP molecules made?
in glucose catabolism in prokaryotes
order to energy sources when glucose is low:
carbs, fat, protein
what hydrolyzes fat when it is needed for energy?
lipases hydrolyze fat into FAs and glycerol
glycerol from fat can be oxidized into what?
PGAL (glyceraldehyde 3-phosphate)
once fatty acids are activated they enter into….
the mitochondria
what process do FAs undergo in the mitochondria?
beta-oxidation
what happens in beta-oxidation?
FAs are converted into acetyl CoA which then enters into the Krebs Cycle
how many NADH and FADH2 molecules are made from one beta-oxidation rotation?
1 of each
what high-energy compound holds the most energy?
fat
what is a transamination reaction?
proteins exchange an amino group for a ketone group
what do proteins become when being used for energy?
keto acids
what is oxidative deamination?
ammonia molecule is removed from a protein
what is ammonia converted to in humans for excretion?
urea
what is converted to what in photosynthesis?
CO2 and H20 are made into glucose and oxygen
where does photosynthesis take place in plants?
chloroplasts
do bacteria have chloroplasts?
no
is photosynthesize oxidation or reduction?
reduction
what are the light reactions of photosynthesis?
solar energy is converted to ATP and NADPH
what are the dark reactions of photosynthesis?
carbon fixation (CO2 is incorporated into molecules)
what part of the chloroplast absorbs photons of light?
chlorophylls
what happens when chlorophylls absorbs photons?
electrons are excited to a higher level
what is produced in cyclic phosphorylation?
ATP from ADP and Pi
in noncyclic phosphorylation, the high energy electrons don’t return to 9700. what happens instead?
they are transferred to NADP+ to make NADPH
net results of noncyclic electron flow:
NADPH, ATP and photolysis of water
the dark reactions use ATP and NADPH produced by light reactions to do what?
reduce CO2 to carbohydrates
what is the product of the Calvin Cycle
phosphoglyceraldehyde from CO2 (3 turns)
compare the Calvin Cycle to the Kreb’s Cycle:
CO2 is fed to Calvin Cycle/Kreb’s produces CO2;
NADPH reducing power is used in CC/ NADH is used in Kreb’s;
energy is used in Calvin/energy is made in Kreb’s
what is the end product of photosynthesis?
phosphoglyceric acid (PGAL)
how do cnidarians (protozoa and hydra) respirate?
simple diffusion through membrane
how do annelids respirate?
cutaneous respiration when circulation brings O2 to cells and CO2 to the skin for excretion
how do arthropods respirate?
trachea reach the surface in spiracles. NO O2 carrier.
where does gas exchange between the air in the lungs and the blood in the circ. system happen in humans?
across the alveoli
what is the purpose of ventilation?
take in O2 and eliminate CO2
what increases during inhalation?
thoracic cavity volume…less pressure in the lungs
what regulates ventilation?
medulla oblongata which stimulates the intercostal muscles/diaphragm
oxygen goes from the alveoli to the blood; CO2 goes from…
the blood to the alveoli to be exhaled from the body
what prevents the surface tension of water on the alveoli from causing a lung to collapse?
pulmonary surfactant which helps improve pulmonary compliance/elasticity
