The best answer is B - Proteins.
Proteins make up enzymes, or to put it another way enzymes are made up of protein. It is enzymes that speed up the chemical reactions. Enzymes are organic catalysts, substances that speed up a (biochemical) reaction but do not take part in the reaction and remain unchanged at the end of the reaction.
In man, there are many enzymes. The majority of these are found in the digestive system where they greatly aid the process of food breakdown from complex molecules to simple molecules. Examples include salivary amylase found in saliva, which begins the gradual breaking down of starch into glucose right from the moment food is placed in the mouth and mixed with saliva. Pepsin in the stomach breaks down protein.
The event order should be:
1. Ingesting food, the small bowel filled with food solutes and become hypertonic. It will attract water from the blood which is hypotonic
2. Food digested, some of it absorbed. The osmotic pressure inside bowel will be reduced.
3. All food is absorbed, the osmotic pressure reduced significantly makes it hypotonic. The blood attracts water as it is hypertonic. This will increase the blood volume
A difference between plant cells and animal cells is that most animal cells are round whereas most plant cells are rectangular. Plant cells have a rigid cell wall that surrounds the cell membrane. Animal cells do not have a cell wall.
After a vigorous workout without consuming significant amounts of water, the specific gravity will have a higher concentration. A vigorous workout increases the breakdown of glucose, without enough water to flush it out it remains in the urine;meaning specific gravity will be high because of the of the high glucose content.
There are various imaging techniques in collecting information about the brain and its adjacent structures. To enumerate, there are the cranial ultrasound (for children with cranial sutures that are not closed yet), cranial CT-scan, cranial MRI, brain PET scan, and cranial functional MRI. Only the brain PET scan and cranial functional MRI can collect information about the brain function by detecting fluorodeoxyglucose (FDG) in the brain as this lights up in functional areas of the brain in PET scan; and by detecting brain activity through changes in blood flow in cranial functional MRI.
<em>While it is not an imaging technique, electroencephalogram or EEG can detect brain function.</em>