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Enzymes catalyze biochemical reactions by ________

A. Lowering the potential energy of the products

B. Separating inhibitors from products

C. Forming a complex with the products

D. Lowering the activation energy of the reaction

Answer Explanation:

Enzymes act as catalysts for biochemical reactions. A catalyst is not consumed in a reaction, but rather lowers the activation energy for that reaction. The potential energy of the substrate and the product remain the same, but the activation energy-the energy needed to make the reaction progress can be lowered with the help of an enzyme.

Therefore, the Correct Answer is D.

More Questions on TEAS 7 Science

  • Q #1: Which of the following is NOT a characteristic of enzymes?

    A. They change shape when they bind their substrates.

    B. They can catalyze reactions in both forward and reverse directions.

    C. Their activity is sensitive to changes in temperature.

    D. They are always active on more than one kind of substrate.

    Answer Explanation

    Enzymes are substrate-specific. Most enzymes catalyze only one biochemical reaction. Their active sites are specific for a certain type of substrate and do not bind to other substrates and catalyze other reactions.

  • Q #2: Which of these does NOT match the nitrogenous base to the nucleobase?

    A. Purine: Adenine

    B. Purine: Thymine

    C. Pyrimidine: Uracil

    D. Pyrimidine: Cytosine

    Answer Explanation

    There are two types of nitrogenous bases: purine and pyrimidine bases. Purine bases have two rings in their structure and consist of adenine and guanine. Pyrimidine bases only have one ring in their structure and consist of thymine and cytosine (DNA) and uracil and cytosine (RNA). Therefore, the correct answer is B since thymine is a pyrimidine.

  • Q #3: Which of the following is NOT provided as a result of the valid research and observations recorded by scientists?

    A. A better understanding of the physical world

    B. The ability to predict possible outcomes affected by actions

    C. The ability to prevent earthquakes and other natural disasters

    D. The creation of various substances and technologies that enhance our world

    Answer Explanation

    Scientists make observations, gather data, and complete research over many years in order to compile knowledge that will provide insight into future disasters, such as earthquakes, storms, and global warming. Although science can be used to predict earthquakes and other natural disasters, there is currently no way of preventing them from occurring.

  • Q #4: A chemistry experiment is performed to determine the effect of a nonvolatile solute on the boiling point of water. Three trials are performed in which 10 mg, 20 mg, and 30 mg of salt are added to 500 mL of distilled water. Each solution is heated on a hot plate, and the elevated boiling points are recorded. Determine the dependent and independent variables in this question.

    A. The independent variable is the amount of salt, and the dependent variable is the temperature at which the water boils.

    B. The independent variable is the amount of water, and the dependent variable is the temperature at which the water boils.

    C. The independent variable is the temperature at which the water boils, and the dependent variable is the amount of salt.

    D. The Independent variable is the amount of salt, and the dependent variable is the amount of water.

    Answer Explanation

    In a scientific experiment, the dependent variable is the condition that is being tested and measured. The independent variable is the condition that is being changed or controlled. In this example, the amount of salt is varied, and the boiling point of water is measured. Therefore, the independent variable is the amount of salt, and the dependent variable is the temperature at which the water bolls.

  • Q #5: What is the name for the physical presentation of an organism's genes?

    A. Phenotype

    B. Species

    C. Phylum

    D. Genotype

    Answer Explanation

    Phenotype is the physical presentation of an organism's genes. In other words, the phenotype is the physical characteristics of the organism. Phenotype is often contrasted with genotype, the genetic makeup of an organism. The genotype of the organism is not visible in its presentation, although some of the characteristics encoded in the genes have to do with physical presentation. A phylum is a group of classes that are closely related. A species is a group of like organisms that are capable of breeding together and producing similar offspring.

  • Q #6: When animals eat, insulin is released from the pancreas, stimulating glucose uptake by the liver. When glucose levels drop, the pancreas reduces insulin release. This is an example of which mechanism for maintaining homeostasis?

    A. Negative feedback

    B. Positive feedback

    C. Stress response

    D. Parasympathetic regulation

    Answer Explanation

    Maintaining homeostasis means that conditions are kept stable and relatively constant. Negative feedback is a mechanism used to reverse or minimize changes in a system. In this example, negative feedback is used to keep the body's glucose and insulin levels stable. Positive feedback (B) is a mechanism that Increases changes in a system. A stress response (C) describes the body's reaction to threats or pressures. Parasympathetic regulation (D) refers to activities of the nervous system, including slowing the heart rate and boosting Intestinal activity.

  • Q #7: Where is the gastrocnemius vein in relation to the femoral vein?

    A. Lateral

    B. Distal

    C. Superior

    D. Ventral

    Answer Explanation

    The gastrocnemius vein is found in the calf. The femoral vein is found in the proximal anterior thighs/pelvis.

    Since the gastrocnemius vein is found below the femoral vein it is distal or inferior to the femoral vessel.

  • Q #8: Which structure of the nervous system carries action potential in the direction of a synapse?

    A. Cell body

    B. Axon

    C. Neuron

    D. Myelin

    Answer Explanation

    Axons carry action potential in the direction of synapses. Axons are the long, fiber-like structures that carry information from neurons. Electrical impulses travel along the body of the axons, some of which are up to a foot long.

    A neuron is a type of cell that is responsible for sending information throughout the body. There are several types of neurons, including muscle neurons, which respond to instructions for movement; sensory neurons, which transmit information about the external world; and interneurons, which relay messages between neurons. Myelin is a fat that coats the nerves and ensures the accurate transmission of information in the nervous system.

  • Q #9: Which of the following is NOT true concerning correlation?

    A. Correlation can show the relationship between variables.

    B. Correlation can show cause and effect.

    C. Correlation can show linear relationships.

    D. Correlation can show nonlinear relationships.

    Answer Explanation

    Correlations may be positive or negative and linear or nonlinear. However, correlation does not determine cause and effect. Correlation does not necessarily mean causation.

  • Q #10: Where is the scapula in relation to the olecranon?

    A. Distal

    B. Lateral

    C. Ventral

    D. Superior

    Answer Explanation

    The scapula, commonly known as the shoulder blade, is above the olecranon, commonly known as the elbow. Conversely, the olecranon is distal or inferior to the scapula.