The answer is <span>B. contains enzymes that begin the breakdown of proteins.
Saliva is watery substance secreted by salivatory glands. <em>It cleanses the mouth</em> and maintenance oral hygiene. <em>It moistens the food</em>, so the created food bolus could easier pass into the esophagus. It also <em>carries food chemicals to taste receptors</em> so they can be tested. It contains enzymes involved in the food digestions. Some of them are amylase, which begins the breakdown of the starch, and lipase, which begins the breakdown of triglycerides. <u>There are no enzymes in the saliva that break down proteins</u>.</span>
Answer:
Cellular respiration involves many reactions in which electrons are passed from one molecule to another. Reactions involving electron transfers are known as oxidation-reduction reactions (or redox reactions).
The planetary body that Spirit was designed to explore the wide ranges of soil and rocks for clues of the water activity on Mars. Spirit specifically landed at the Gusev Crater which was before, a possible lake in a giant crater.
Answer: Single cell organisms dont need a respiratory system because oxygen and carbon-dioxe diffuses between their body tissues and the enviorment.
In this question in which is the major source then of free oxygen in the earth's Proterozoic atmosphere is being produce by the evaporation of the ocean water. Hope this answer would be of big help to this assignment then.