Digestive enzymes<span> speed up reactions that break down large molecules of carbohydrates, proteins, and fats into smaller molecules the body can use. Without digestive </span>enzymes<span>, animals would not be able to break down food molecules quickly enough to provide the energy and nutrients they </span>need<span> to </span><span>survive</span>
Nature does = environmental stress or changes
Answer: c. proteasome
Explanation:
Proteasomes are extremely important multi-catalytic proteases and are involved in various cellular functions. The proteasome is an essential component of eukaryotic cells and is responsible for the ATP-dependent proteolytic degradation of most cellular proteins. They are present in the nucleus and cytosol and can represent up to 1% of total cell proteins. Proteasomes generally degrade proteins to small peptides, most of which are rapidly hydrolyzed by cytoplasmic exopeptidases. It catalyzes the rapid degradation of many enzymes, regulatory proteins, and eliminates abnormal proteins resulting from mutation or damaged proteins. The inability of this cellular organelle can lead to neurodegenerative diseases, such as Parkinson´s disease.
Scientists found that the first living things were likely prokaryotic because eukaryotic are evolved from the prokaryotic only.
<h3>What do you mean by Natural selection?</h3>
Natural selection may be defined as favorable variations that assist the organisms to survive and reproduce in a particular habitat.
Individuals that are better suited to their environment are likely to have more offspring and pass their genetic material on to future generations. This theory is referred to as Natural selection.
Scientists hypothesize that oxygen began to accumulate in the Earth's atmosphere after the appearance of living things with the ability to Photosynthesize.
To learn more about Photosynthesis, refer to the link:
brainly.com/question/19160081
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Answer: By us people breathing in oxygen and breathing out carbon dioxide.