Q: Answer the following question given this paragraph: 24.2 Carbohydrate Metabolism Metabolic enzymes catalyze catabolic reactions that break down carbohydrates contained in food. The energy released is used to power the cells and systems that make up your body. Excess or unutilized energy is stored as fat or glycogen for later use. Carbohydrate metabolism begins in the mouth, where the enzyme salivary amylase begins to break down complex sugars into monosaccharides. These can then be transported across the intestinal membrane into the bloodstream and then to body tissues. In the cells, glucose, a six-carbon sugar, is processed through a sequence of reactions into smaller sugars, and the energy stored inside the molecule is released. The first step of carbohydrate catabolism is glycolysis, which produces pyruvate, NADH, and ATP. Under anaerobic conditions, the pyruvate can be converted into lactate to keep glycolysis working. Under aerobic conditions, pyruvate enters the Krebs cycle, also called the citric acid cycle or tricarboxylic acid cycle. In addition to ATP, the Krebs cycle produces high-energy FADH2 and NADH molecules, which provide electrons to the oxidative phosphorylation process that generates more high-energy ATP molecules. For each molecule of glucose that is processed in glycolysis, a net of 36 ATPs can be created by aerobic respiration. Under anaerobic conditions, ATP production is limited to those generated by glycolysis. While a total of four ATPs are produced by glycolysis, two are needed to begin glycolysis, so there is a net yield of two ATP molecules. In conditions of low glucose, such as fasting, starvation, or low carbohydrate diets, glucose can be synthesized from lactate, pyruvate, glycerol, alanine, or glutamate. This process, called gluconeogenesis, is almost the reverse of glycolysis and serves to create glucose molecules for glucose-dependent organs, such as the brain, when glucose levels fall below normal. Q: Metabolic enzymes catalyze catabolic reactions that break down what? A:

OPTIONS:
- proteins
- lipids
- impurities
- carbohydrates

A: carbohydrates

Q: Answer the following question given this paragraph: Interspecific competition often leads to extinction . The species that is less well adapted may get fewer of the resources that both species need. As a result, members of that species are less likely to survive, and the species may go extinct. Q: What does interspecific competition between species often lead to? A:

OPTIONS:
- evolution
- symbiosis
- immigration
- extinction

A: extinction

Q: Answer the following question given this paragraph: Extensive properties vary according to the amount of matter present. Examples of extensive properties include mass, volume, and length. Q: What are mass, volume, and length an example of? A:

OPTIONS:
- extensive compounds
- dynamic properties
- fantastic properties
- extensive properties

A: extensive properties

Q: Answer the following question given this paragraph: After hatching, most arthropods go through one or more larval stages before reaching adulthood. The larvae may look very different from the adults. They change into the adult form in a process called metamorphosis. During metamorphosis, the arthropod is called a pupa. It may or may not spend this stage inside a special container called a cocoon. A familiar example of arthropod metamorphosis is the transformation of a caterpillar (larva) into a butterfly (adult) (see Figure below ). Distinctive life stages and metamorphosis are highly adaptive. They allow functions to be divided among different life stages. Each life stage can evolve adaptations to suit it for its specific functions without affecting the adaptations of the other stages. Q: What is the process of larva becoming an adult called? A:

OPTIONS:
- parthenogenesis
- synthesis
- evolution
- metamorphosis

A:
metamorphosis