A stem is what keeps the plant together and supports their leaves
B. STEMS
Answer:
When the required direction of transport is opposed to concentration levels, a cell <u>will </u> expend energy to force<u> ions</u> across its membrane.
Explanation:
If the concentration gradient is opposite to the direction of transport of minerals, then the cell will use energy to transport mineral ions from a lower concentration to a higher concentration. The most common process through which this happens is termed as the active transport.
The process of active transport is opposite to passive transport. In passive transport, molecules move from a higher concentration to a lower concentration.
An enzyme is an organic catalyst.
<h3>
What is an enzyme?</h3>
Enzymes are proteins that help speed up metabolism or the chemical reactions in our bodies.
They build some substances and break others down.
All living things have enzymes. Our bodies naturally produce enzymes.
But enzymes are also in manufactured products and food.
Examples of specific enzymes:
Amylase: In the saliva, amylase helps change starches into sugars.
Maltase: This also occurs in the saliva, and breaks the sugar maltose into glucose.
Trypsin: These enzymes break proteins down into amino acids in the small intestine.
To learn about enzymes, refer
https://brainly.in/question/15327487
#SPJ4