exam 2 hw and review Flashcards
Which structure is NOT part of the endomembrane system?
Peroxisome
Which structure is the site of the synthesis of proteins that may be exported from the cell?
rough ER
Which of the following statements correctly describes some aspect of protein secretion from prokaryotic cells?
Proteins secreted by prokaryotes are synthesized on ribosomes bound to the cytoplasmic surface of the plasma membrane.
The liver is involved in detoxification of many poisons and drugs. Which of the following structures is primarily involved in this process and, therefore, abundant in liver cells?
smooth ER
In a plant cell, DNA may be found _____.
in the nucleus, mitochondria, and chloroplasts
Vinblastine, a drug that inhibits microtubule polymerization, is used to treat some forms of cancer. Cancer cells given vinblastine would be unable to _____.
separate chromosomes during cell division
The fluid mosaic model of the membrane proposes that membranes _____.
consist of protein molecules embedded in a fluid bilayer of phospholipids
The membranes of winter wheat are able to remain fluid when it is extremely cold by _____.
increasing the percentage of unsaturated phospholipids in the membrane
Some regions of the plasma membrane have a higher concentration of cholesterol molecules. At higher temperatures, these regions _____.
are less fluid than the surrounding membrane
Why are lipids and proteins free to move laterally in membranes?
There are only weak hydrophobic interactions in the interior of the membrane.
What is the role of chief cells within the stomach?
Secrete pepsinogen, an inactive form of the protease, pepsin
The agents that help emulsify fats are stored in the ______.
gallbladder
Digestion of fats occurs in the ____.
small intestine
Stomach cells are moderately well adapted to the acidity and protein-digesting activities in the stomach by having _____.
a thick, mucous secretion and active mitosis of epithelial cells
The highest rate of nutrient absorption occurs in the _____.
small intestine
The absorption of fats differs from that of carbohydrates in that _____.
most absorbed fat first enters the lymphatic system, whereas carbohydrates directly enter the blood
In a healthy person, after a large meal, the production of _____ will increase. After fasting, the production of _____ will increase.
insulin; glucagon
Constipation can result from the consumption of a substance that _____.
promotes water reabsorption in the large intestine
All of the following are part of a prokaryotic cell EXCEPT _____.
- A chromosome
- A plasma membrane
- All are part of a prokaryotic cell
- Ribosomes
all are part of a prokaryotic cell
The nuclear lamina is an array of filaments on the inner side of the nuclear membrane. If a method were found that could cause the lamina to fall into disarray, what would you most likely expect to be the immediate consequence?
A change in the shape of the nucleus
Which of the following is not a reason why we need to ingest and digest food?
- Obtain essential nutrients
- Provides chemical energy for the body
- To generate the raw materials need for the biosynthesis of large biological molecules
- All are reasons
all are reasons
Which of the following is not an essential nutrient?
nucleic acids
Certain nutrients are considered “essential” in the diets of some animals because _____.
these animals are not able to synthesize these nutrients
Iron is an example of an essential _____.
mineral
One a Day multivitamin for women contains only 21% of the daily recommended value of vitamin K. The most likely reason that is found at less than 100% is ____.
it is dangerous to overdose on fat-soluble vitamins
Which of the following are not part of the alimentary canal?
liver
The function of mechanical digestion is to break down large chunks of food into smaller pieces. Why is this important? Smaller pieces of food _____.
have more surface area for chemical digestion than do larger pieces of food
In the digestive system, peristalsis is _____.
smooth muscle contractions that move food along the esophagus
Which of the following is not a component of saliva?
proteases
Which class(es) of large biological molecules undergo chemical digestion in the oral cavity?
carbohydrates
