Mastering Biology Chapter 6

Cellular respiration accomplishes two major processes: (1) it breaks glucose down into smaller molecules, and (2) it harvests the chemical energy released and stores it in ATP molecules. By the end of _____, the breakdown of glucose is complete; most ATPmolecules are produced during _____.

the Citric Acid cycle ... electron transport

Which part(s) of cellular respiration take(s) place in the mitochondria?

the citric acid cycle and the electron transport chain

Sunlight is essential for the varied life on Earth. Sunlight provides energy to photosynthetic organisms by providing __________.

the energy necessary to power the rearrangement of chemical bonds in H2O and CO2---- This is what photosynthesis accomplishes in the conversion of water and carbon dioxide to sugars.

NADH and FADH 2 are important in cellular respiration because they deliver high-energy electrons to the electron transport system. Electron transport produces _____ ATP molecule(s) per NADH molecule and _____ ATP molecules(s) perFADH 2 molecule.

three ... two

The energy released from the redox reactions in the electron transport chain is used by the cell to make _______________.

ATP

In cellular respiration, organic molecules become oxidized as ________ picks up electrons and H+ and becomes reduced to NADH.

NAD+

During fermentation, __________ that was produced during glycolysis is converted back to __________.

NADH; NAD+---- NADH molecules produced during glycolysis are converted back to NAD+ during fermentation. This NAD+ is used again in a new round of glycolysis.

gas produced by photosynthesis

O2

What is the role of oxygen in cellular respiration?

Oxygen accepts high-energy electrons after they are stripped from glucose.

In cellular respiration, oxygen becomes ____________ to water (H2O) as it gains electrons (in hydrogen atoms) that came from glucose.

reduced

In the first stage of cellular respiration (glycolysis), two molecules of pyruvate are produced. In the remaining stages of cellular respiration, a number of additional products are produced, such as __________. These other stages occur in the __________.

ATP...mitochondria---- ATP, CO2, and H2O are the products of cellular respiration. As pyruvate is "groomed," it is moved into a mitochondrion where the remaining stages of cellular respiration occur.

gas we exhale

CO2

water

H2O

Drag the labels onto the equation to identify the inputs and outputs of cellular respiration.

INPUTS--- 1 glucose(fuel) +6 O2(gas we inhale) OUTPUTS--- 6CO2 (gas we exhale) + 6 H2O (water) + ATP (energy packets that cells use to do work

What is the ultimate fate of the electrons that are stripped from glucose during cellular respiration?

They are used to form water---- At the end of the electron transport chain, the electrons and hydrogen ions are used to reduce oxygen to form water.

Using the ATP generated during cellular respiration, the intermediates of glycolysis and the citric acid cycle, such as pyruvate and acetyl CoA, can be siphoned off and used to __________.

build amino acids, fats, and sugars---- The beauty of many metabolic pathways is that they can be used for both the breaking down of compounds for energy, or to synthesize complex macromolecules, depending on the needs of the cell and the availability of energy.

The transfer of ___________ from one molecule to another is an oxidation-reduction reaction, or redox reaction.

electrons

Each turn of the citric acid cycle generates one ATP and ___ additional energy-rich molecules: __________.

four; 3 NADH and 1 FADH2---- The citric acid cycle generates 3 molecules of NADH and 1 molecule of FADH2. These molecules carry high energy electrons that will be delivered to the electron transport chain.

Foods that plants produce

glucose

Glycolysis is the multi-step breakdown of _____. Several different _____ play a role in this process.

glucose ... enzymes

A molecule that functions as the electron donor in a redox reaction __________.

loses electrons and becomes oxidized---- In cellular respiration, glucose is oxidized when it loses electrons in hydrogen atoms. Oxygen is reduced as it gains electrons in hydrogen atoms.

In cellular respiration, glucose becomes __________ to carbon dioxide (CO2) as it loses electrons (in hydrogen atoms).

oxidized

Unlike the Citric Acid cycle and electron transport, glycolysis occurs _____.

in the cytoplasm

Cellular respiration requires fuel (glucose) and oxygen gas. The main process that produces these inputs is _____.

photosynthesis

NADH delivers electrons to an electron transport chain, which passes the electrons through carrier molecules in a series of redox reactions to the final electron acceptor, ____________.

oxygen

Which part(s) of cellular respiration require(s) oxygen gas?

the citric acid cycle and the electron transport chain NOT glycolysis

In electron transport, high-energy electrons "fall" to oxygen through a series of reactions. The energy released is used to _____.

transport protons into the intermembrane space of the mitochondria, where they become concentrated. They then flow back out into the the inner compartment (matrix) of the mitochodria. On the way back, protons turn ATP synthase turbines and produce ATP.

What is/are the most important output(s) of glycolysis?

two pyruvic acid and two NADH molecules