Pepsin, a common enzyme found in the stomach, is most active at ph values between 0.5 and 2.5. it works slowly between ph values of 2.6 and 3.4. beyond a ph of about 3.5, it becomes completely inactive. why does this happen? a) the enzyme inactivates because it melts into a liquid when it is not at the right ph. b) the protein chain in the enzyme is denatured, permanently inactivating it as the ph approaches 7. c) the enzymes slow down, because changing the ph changes the temperature as well, and affects the reaction. eliminate d) the enzyme's active site contracts into the wrong shape, but this is always reversible if the right ph is restored.

Asap timed! 1. ice core samples from glaciers ice caps contain bubbles of ancient atmosphere that are in layers based on age. what questions are scientists most interested in? a. how the amount of water vapor needed to make the ice has changed b. how the amount of ozone has changed over time.c. how the amount of ice in each layer has changed over time d. how the amount of carbon dioxide has changed over time 2. what produces milankovich cycles ? a. sunspots ams solar flare on the suns surface b. changes in the earths orbit c. gravitational changes bases on the position of the sun and the moond. cycles of vegetation that result in desert and rainforest conditions

Why is the theory of evolution important? it disproves all other theories about how life began. it provides a topic for debate. it is a unifying concept in biology. it explains how life began. i know for sure, it is not "it is a unifying concept in biology."

Anton created a chart listing different types of materials. which best complete the chart?