Biology Test Questions

In the human body, muscle cells complete aerobic respiration in the presence of oxygen. Are muscle cells able to function without oxygen?

No. Athletes depend upon the efficiency of their respiratory and circulatory systems to supply oxygen to their muscles to support aerobic respiration for long periods of time.

Ub the process of glycolysis, four ATP molecules are synthesized from four ADP molecules. Why does glycolysis not yield four molecules of ATP?

Because 2 ATP molecules are required to start the process.

Bree is using the following word equation to model a cellular process. oxygen + glucose --> carbon dioxide + water + energy Which process, if any, could Bree be modeling accurately?

Cellular Respiration

ATP is produced in all stages of cellular respiration. Describe the process of ATP synthesis in the electron transport chain.

During electron transport, H+ ions build up in the innermembrane space, making it positively charged relative to the matrix. In turn, the other side becomes negatively charged so that the membrane itself becomes a sort of biological "battery" that can power the synthesis of ATP.

Glycolysis is the first stage of cellular respiration and is an anaerobic process. During glycolysis, glucose is converted to two molecules of pyruvic acid. How is glycolysis kept functioning during cellular respiration?

Fermentation

What is the role of oxygen gas (O2), if any, in glycolysis?

It does not have a role. Glycolysis does NOT require oxygen.

Savannah is asked to explain the locations of the stages of cellular respiration. What location should she give for the site of the Krebs cycle reactions?

Matrix of the mitochondria

Earths atmosphere is about 21 percent oxygen. This percentage gas remained about the same throughout human history and earlier. How have cellular respiration and photosynthesis helped maintain relatively constant oxygen levels?

Photosynthesis removes carbon dioxide from the atmosphere, and cellular respiration puts it back. Photosynthesis releases oxygen into the atmosphere, and cellular respiration uses that oxygen to release energy from food.

One of the end products of cellular respiration is ATP, which is the molecule that cells use for energy. How is ATP produced during cellular respiration?

The breaking down of glucose into energy (Which is ATP).

The enzyme ATP synthase is a protein that contains a small channel. How is the movement of hydrogen ions through the channel useful in the function of the enzyme?

The charge difference across the membrane forces H+ ions through channels in these enzymes causes the ATP synthase to spin. With each rotation, the enzyme grabs an ADP molecule and attaches a phosphate group, producing ATP.

Milo is analyzing the steps of cellular respiration. His goal is to quantify the amount of useful chemical energy that cellular respiration can generate from one molecule of glucose. Which of these chemical changes that occur during cellular respiration would be MOST USEFUL for Milo to track and identify?

The total products of cellular respiration, which include 2, 2, 32

Xavier and Jill are practicing the 100-meter sprint. Which statement BEST describes the metabolic pathways their muscles will utilize to produce the quick energy needed for the intense exercise?

glycolysis begins glucose metabolism, and in the absence of oxygen, lactic acid fermentation takes over.

Mariana eats an orange. Which statement describes the ultimate source of the energy that her body receives when she digests the orange?

the light energy that originates from the sun provides the energy to grow oranges, which contain macromolecules

The Krebs cycle consists of many small steps, each catalyzed by an enzyme. What is another name for the Krebs cycle?

Citric acid cycle

Jose and Rema are making sourdough bread. They have been feeding the starter dough for a week now, and it has undergone lactic acid fermentation. They mix the dough and add a portion of the starter, which will give the bread its famous texture and sour flavor. What process will occur next to make the dough rise?

Alcoholic fermentation takes place and ethyl alcohol and CO2 gas are formed, creating pockets in the dough

Natasha is making a model of cellular respiration. Her models shows the pathway followed when there is enough oxygen available. What does Natasha's model show?

an aerobic pathway consisting of glycolysis, the krebs cycle, and the electron transport chain

The molecules in the food we eat contain chemical energy stored in chemical bonds. Which statement best explains how this energy is released?

chemical bonds in food molecules are broken, releasing energy and allowing cells to use the energy to make ATP