Biology Cellular Respiration

What is the correct general equation for cellular respiration?

C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + ATP energy [Cellular respiration extracts energy from glucose to produce smaller energy packets]

In an experiment, mice were fed glucose containing a small amount of radioactive carbon. The mice were closely monitored, and in a few minutes, radioactive carbon atoms showed up in___________. - ATP - Water - Heat - Carbon dioxide

Carbon dioxide [Cellular respiration, or the oxidization of glucose, involves the release of CO2]

During electron transport, energy from _____ is used to pump hydrogen ions into the _____.

NADH and FADH2... Intermembrane space [The energy released as electrons, which have been donated by NADH and FADH2, is passed along the electron transport chain and used to pump hydrogen ions into the inter membrane space]

An electron carrier, such as __________, acts as an energy-storage molecule when it is __________. - NAD+...reduced - NADH...oxidized - NAD+...oxidized - NADH...reduced

NADH...reduced [NADH is the reduced form of this molecule and it carries high energy electrons. This makes it an energy-storage molecule]

In cellular respiration, most ATP molecules are produced by _____.

Oxidative phosphorylation [This process utilizes energy released by electron transport]

A muscle cell deprived of molecular oxygen will convert glucose to lactic acid to __________.

Recycle NADH through fermentation [During lactic acid fermentation, pyruvate is reduced directly by NADH to form lactate. This recycles NAD+, so the cycle continues

In citric acid cycle, ATP molecules are produced by_____.

Substrate-level phosphorylation [A phosphate group is transferred from GTP to ADP]

Most NADH molecules generated during cellular respiration are produced during: - Glycolysis - The reduction of oxygen - The electron transport chain - The citric acid cycle

The citric acid cycle [There are 6 NADH molecules produced by the citric acid cycle per molecule of glucose. Two molecules of FADH2 are also produced by this cycle, which makes it a big source of high energy electron carriers]

In whom is heat-generating brown fat most active?

The first study suggests that weight and temperature might have an effect on brown fat activity levels; the second study confirms that thin individuals exposed to cold temperatures had the highest brown fat activity levels

The proximate (immediate) source of energy for oxidative phosphorylation is _____.

The kinetic energy that is released as hydrogen ions diffuse down their concentration gradient [Concentration gradients are a form of potential energy]

Where does the majority of the energy in a molecule of glucose go? Other than as ATP

The majority of the energy in a molecule of glucose is lost as heat

How do food molecules reach the body's cells and fuel cellular respiration?

- Eating food provides fuel and building blocks for your body - After food is broken down in the digestive system, it is transported to cells via the circulatory system - Fuel molecules are broken down further in glycolysis and the citric acid cycle - ATP is produced with the help of the electron transport chain

Describe oxidative phosphorylation

- Final stage of cellular respiration - Generates ATP - Uses a series of membrane proteins known as the electron transport chain in which electrons from FADH2 and NADH are passed from electron carrier to carrier - Final electron acceptor is oxygen - A pump brings H+ molecules into inter membrane space, which creates an H+ concentration gradient - Oxidative phosphorylation uses process of chemiosmosis, which uses energy stored in the H+ concentration gradient, to drive H+ through the ATP synthase - ATP synthase catalyzes the phosphorylation of ADP, which produces ATP

For each glucose that enters glycolysis, _____ NADH enter the electron transport chain.

10 [For each glucose molecule that enters glycolysis, a total of 10 NADH are produced--2 are produced in glycolysis, 2 are produced in acetyl CoA production, and 6 are produced in the citric acid cycle]

In cellular respiration, which of the following outcomes is the result of electrons moving through the electron transport chain (or its components)? - Carbon dioxide is formed - ADP is phosphorylated to make ATP - Oxygen gas is formed - A proton gradient is formed

A proton gradient is formed [The energy released by the electron transport chain is used to create a proton gradient across the inner mitochondrial membrane. This allows the production of ATP by chemiosmosis]

Which of the following processes takes place in the cytosol of a eukaryotic cell? - Citric acid cycle - ATP production by ATP synthase - Electron transport chain - Acetyl CoA formation - Glycolysis

Glycolysis [Glycolysis, the breakdown of glucose into two molecules of pyretic acid, takes place in the cytosol, outside the mitochondria]

Which stage of cellular respiration appears to have evolved first?

Glycolysis [Glycolysis can occur in the absence of oxygen and evolved prior to oxygenic photosynthesis]

Correct sequence of steps as energy is extracted from glucose during cellular respiration

Glycolysis Acetyl CoA Citric Acid Cycle Electron Transport Chain [Glycolysis produces pyretic acid, which enters the mitochondrion. There, it is converted to acetyl CoA, which enters the citric acid cycle. Electron carriers bring electrons from the first three steps to the electron transport chain, and ATP is made]

A chemist has discovered a drug that blocks phosphoglucoisomerase, an enzyme that catalyzes the second reaction in glycolysis. He wants to use the drug to treat people with bacterial infections. However, he can't do this because _____. - Glycolysis produces so little ATP that the drug will have little effect - Bacteria do not perform glycolysis - Human cells also perform glycolysis; the drug might also poison them - Bacteria are facultative anaerobes; they usually don't need to perform glycolysis

Human cells also perform glycolysis; the drug might also poison them [The chemist's drug could have a negative effect on human cells]

A scientist wants to study the enzymes of the citric acid cycle in eukaryotic cells. What part of the cell would she use as a source of these enzymes? - Mitochondrial matrix - Cytoplasm - Plasma membrane - Mitochondrial inner membrane

Mitochondrial matrix [The water-soluble citric acid cycle intermediates and enzymes of a eukaryotic cell are found in the mitochondrial matrix, where the newly synthesized NADH and FADH2 diffuse to proteins of the electron transport chain held within the inner mitochondrial membrane. The matrix corresponds to the cytoplasm of the bacterium from which mitochondria are descended.

In what organelle would you find acetyl CoA formation, the citric acid cycle, and the electron transport chain? - Chloroplast - Lysosome - Nucleus - Mitochondrion - Golgi apparatus

Mitochondrion [All the steps of cellular respiration except glycolysis take place in the mitochondrion]

Describe the citric acid cycle

This process produces some ATP and carbon dioxide in the mitochondrion [The citric acid cycle breaks down carbon molecules, releasing carbon dioxide and forming some ATP]

Describe glycolysis

This process splits glucose in half and produces 2 ATPs for each glucose. [In glycolysis, glucose is split into two molecules of pyruci acid. The released energy is stored in ATP and the electron carrier NADH]

Describe the electron transport chain

This process uses energy captured from electrons flowing to oxygen to produce most of the ATPs in cellular respiration [In the electron transport chain, electrons move from one electron carrier to another, eventually reaching oxygen. The released energy is used to make ATPs]