CH 7 SG Flashcards
Cellular respiration
A series of metabolic reactions that use the energy from carbohydrate fatty acid or amino acid breakdown to produce ATP molecules (mitochondria/cytoplasm(glycolysis))
How are breathing and cellular respiration are related?
a cellular process that produces energy, while simultaneously removing the waste product carbon dioxide, which is then exhaled
Chemical equation for cellular respiration
C6H12O6 + 6O2 ———> 6CO2 + 6H2O + ~32 ATP
Chemical equation for photosynthesis
6CO2 + 6H2O —sunlight/photosynthesis—> C6H12O6 + 6O2
ATP
Nucleotide with three phosphate groups, the breakdown of ATP into ADP plus P makes energy available for energy-requiring processes and cells
What are the anaerobic processes for extracting energy from food?
fermentation and digestion are methods organisms use to extract energy from food without oxygen
reactants, products, and energy yield of alcohol fermentation
It breaks down sugars, like glucose, into ethyl alcohol and CO2, yielding only 2 ATP per glucose molecule, in contrast to the higher energy output of aerobic respiration
What role does oxygen play in the electron transport chain?
(oxygen drives the electrons chain/the oxygen is electronegative, therefore it pulls electrons through the chain)
It acts as the final electron acceptor
Great Oxidation Event (GOE)
(cyanobacteria releasing oxygen into the atmosphere) geological shift in Earth’s atmosphere that happen 2 to 2.5 billion years ago (the transition from an oxygen-free atmosphere to one with a small amount of oxygen) (early life was anaerobic)
photosynthesis
plants convert light energy into chemical energy (sugars) using water and carbon dioxide, occurring in organelles - chloroplasts within plant cells, specifically in the mesophyll tissue of leaves
NADPH
anabolic pathways (photosynthesis)
- a chemical compound that helps cells build molecules and maintain redox balance
NADH
catabolic pathways (cell respiration)
- nicotinamide adenine dinucleotide (NAD) + hydrogen (H).” It occurs naturally in the body and plays a role in generating energy
FADH2
Krebs cycle only (cell respiration)
- (flavin adenine dinucleotide) coenzyme helps transport electrons during cellular respiration
What are the aerobic processes for extracting energy from food?
(for extracting energy from food cellular respiration) involves glycolysis, citric acid cycle, all requiring oxygen to efficiently convert food molecules into usable energy - ATP
reactants, products, and energy yield of lactic acid fermentation
glucose and glycolysis-produced pyruvate, which are converted to lactic acid as a product, with a net energy yield of 2 ATP molecules per glucose molecule
Light reactions
of photosynthesis generate energy carriers, which in turn drive the manufacture of sugars via the Calvin cycle
Main 3 stages of Cellular Respiration:
- glycolysis
- citric acid cycle (or Kreb’s cycle)
- electron transport** (most ATP)
anaerobic
(“without oxygen”) some of your cells can work for short periods without oxygen
Fermentation
(Can make ATP w/o oxygen/harvest of food energy) This relies on glycolysis, the first stage of cellular respiration.
•Produces 2 ATP per glucose.
To harvest food energy during glycolysis…
NAD+ must be present to receive electrons.
–Must anaerobically recycle NADH back to NAD+.
Wastes from fermentation can be…, depending on the species.
ethyl alcohol, lactic acid, or other compounds
Anaerobic digestion
a biological process that breaks down organic materials without oxygen
Energy carriers store energy in…
loosely bounded electrons and hydrogen atoms
The overall effect of all this transfer of electrons during cellular respiration…
is a “downward” trip for electrons
What’s the order for the transfer of electrons?
–from glucose,
–to NADH,
–to an electron transport chain, and
–to oxygen.
Citric Acid Cycle
(Purposes is to make a bunch of energy carriers) biochemical reactions to release the energy stored in nutrients through the oxidation of acetyl-CoA derived from carbohydrates, fats, proteins, and alcohol
(in: Mitochondrion/input: 2 Acetyl CoA/output: 2 ATP, 6 NADH, 2 FADH2, 4 CO2)
Glycolysis
metabolic pathway that converts glucose into pyruvate and, in most organisms, occurs in the liquid part of cells (he universal energy-harvesting process of life) (in:Cytoplasm/input: 1 Glucose
(C6H12O6)/output: 2 ATP, 2 NADH, 2 Pyruvate)
Chemiosmosis
The energy stored by electron transport behaves something like the water behind a dam (things want to diffuse)
oxidative phosphorylation
(oxygen drives the electrons chain) protein complexes and molecules in the mitochondria that transfer electrons to generate cellular energy (ATP) through a process
Redox/Oxidation-Reduction reactions
A paired set of chemical reactions in which one molecule gives up electrons (oxidized) while another molecule accepts electrons (reduced) (these are usually coupled, the pair of reactions)
Preparatory reaction
(In between step 1 and 2) that converts pyruvate from glycolysis into acetyl-CoA, preparing it for the Krebs cycle, and releases CO2 and transfers electrons
(in: Mitochondrion/input: 2 Pyruvate/output: 2 Acetyl CoA, 2 NADH, 2 CO2)
Substrate-level ATP synthesis
where a phosphate group is directly transferred from a high-energy intermediate molecule to ADP (adenosine diphosphate), forming ATP (adenosine triphosphate)
NAD+
(nicotinamide adenine dinucleotide) is a coenzyme for redox reactions
FAD
(flavin adenine dinucleotide) a coenzyme that helps enzymes function and is essential for cellular respiration
Electron Transport Chain
protein complexes and molecules in the mitochondria that transfer electrons to generate cellular energy (ATP) through a process called oxidative phosphorylation
(in: Mitochondrion/input: 10 NADH,
2 FADH2, 6 O2/output: ~32-34 ATP,
6 H2O)
ADP
Nucleotide with two phosphate groups that can except another phosphate group and become ATP
Prokaryotic cells
(Smaller) No membrane-bound organelles, Single circular DNA molecule, Cell wall, Plasma membrane, Ribosomes, Cytoplasm, Flagella, Pili and fimbriae, Plasmids, & Capsule
Eukaryotic cells
(Larger) Plasmas membrane, Cytoplasm, Nucleus, Mitochondria, Endoplasmic Reticulum, Golgi apparatus, Ribosomes, Lysosomes, Cytoskeleton, Centrioles, Nucleolus, Vesicles, & Chloroplasts
ATP Synthase
Has the ability to make ATP by adding an extra phosphate to ADP
Cytochrome molecules
Iron containing proteins that form parts of the electron transport chain
Cristae
The membranous folds that extend into the matrix of a mitochondrion
The electron transport chain receives high-energy electrons from…
NADH and FADH2
As electrons are passed down the electron transport chain, the carrier molecules are first _________ as they pick up electrons, and then _________ as they release the electrons.
reduced; oxidized
Why does FADH produce fewer ATP than NADH?
FADH, donates its electrons to the electron transport chain after NADH, therefore pumping fewer H+.
ATP synthase is able to produce ATP when __________ move through the complex.
H+
ATP produced by chemiosmosis most directly uses the energy of _______ to drive the process.
an H+ gradient
Inside the mitochondria, for each _________ molecule formed, 3 ATP are produced, and for each ________ formed, 2 ATP are produced.
NADH; FADH2
What molecules are recycled during cellular respiration, including all of the enzymes used and the coenzymes?
-NAD+
-CoA
-FAD
In some cells, NADH made during glycolysis in the cytoplasm can only cross the mitochondria membranes by…
a shuttle mechanism that uses one ATP for each NADH.
Before entering the citric acid cycle, fatty acids are converted to…
2-carbon acetyl CoA.
About ________ of the energy available is transferred from glucose to ATP during cellular respiration.
32%
How many ATP are required to shuttle an NADH molecule produced in the cytoplasm to the ETC in the mitochondria?
One ATP per NADH
During cellular respiration, about ________ of the energy from the glucose molecule dissipates as heat.
60%
As the electrons pass from one carrier to the next, energy that will be used to produce ATP molecules is…
captured and stored as a hydrogen ion gradient.
