Exam Two Study Guide Part Two Flashcards
(30 cards)
What do proteins do?
a. enzymes facilitate chemical reactions in our cells
b. structural proteins maintain structural integrity of cells and tissue (e.g., collagen)
c. transport proteins control what goes in and out of cells
d. motor/contractile proteins facilitate movement such as muscle contractions
e. antibodies and other immunoglobulins are proteins that defend against pathogens
Are all proteins capable of carrying out the same functions as other proteins? Why or why not?
No, because proteins differ from each other in their 3-dimensional shape
Both RNA (ribonucleic acid) and DNA (deoxyribonucleic acid) are two…?
Nucleic Acids
Structurally, a gene is a stretch of nucleotides along the length of a DNA molecule. What is longer, a gene or a
DNA molecule?
DNA Molecule
If we think of a nucleic acid as being a chain, we could say the links are letters if
oversimplifying, but if speaking literally, we’d say its links are…?
Nucleotides
How does a single strand of RNA differ from a single strand of DNA?
1) the nucleotides of RNA include the sugar ribose, whereas the nucleotides of DNA instead include the sugar
deoxyribose, which is a ribose sugar that includes only four oxygen atoms rather than ribose’s five oxygen
atoms.
2) they differ in one of the nucleotides that comprise nucleic acids: DNA includes the nucleobase thymine,
whereas RNA includes the nucleobase uracil.
What is longer, a gene or a nucleotide?
Gene
What do DNA and RNA do?
DNA tells RNA how to make proteins, and RNA makes proteins. That’s all you’ll need to know for the
test, but know for life that each gene of a DNA molecule is a recipe for making a protein, and that Messenger
RNA, Ribosomal RNA, and Transfer RNA build each protein.
f we think of a gene as being a chain, we’d say its links are…?
Nucleotides
Why is it mostly correct to say that a chromosome is a DNA molecule? Incidentally, the opposite is not always true
A chromosome is one DNA molecule that has been wrapped around many proteins. You can
visualize a chromosome as one long cord (the DNA) wrapped around many spools (the proteins).
What is the name of the process that allows our cells to extract energy from our food?
Respiration (a.k.a. cellular respiration)
The “point” of this process is to make bunches of..?
ATP
Molecular oxygen (O2) is necessary to fully extract energy from our food. Explain why this is by telling me why
it’s legitimate to think of this process as being akin to electricity.
Hydrogen electrons from glucose or fatty acids, etc. are passed from one protein to another and
eventually to oxygen. This flow of electrons can be thought of as being driven by oxygen pulling these
electrons down a “power line” made of the proteins embedded in inner membrane of mitochondria.
If glucose, fatty acids, and ketones are the molecules from which we extract energy to live, why do we
consider ATP our ultimate energy molecule?
Energy is the capacity to do work, and work is the movement or rearrangement of matter, so the fact
that ATP changes the shape of molecules and causes them to move means that ATP functions as energy.
Why is it incorrect and misleading to say that plants photosynthesize to make oxygen for people?
Plants photosynthesize because they have chlorophylls and other molecules that cause them to
photosynthesize. If a person insists on personifying plants, then one could say that plants photosynthesize to
make food (i.e., sugar) for themselves. Oxygen is simply a waste by-product of the process that both plants
and animals use in cellular respiration.
Why is it incorrect to say that plants breathe carbon dioxide (CO2) and that people breathe oxygen (O2)?
people and plants that live on land breathe air, and air is made of nitrogen (78%), oxygen (21%), and
other molecules, including carbon dioxide (nearly 0.04%)
What causes discomfort when holding one’s breath and the inevitable muscle contractions that force one to
breathe?
buildup of CO2 in the blood
What causes this buildup of CO2 in the blood ?
Cellular Respiration
What would eventually kill us if nothing else did? Why?
oxygen (O2) / because it damages our proteins and DNA when it steals electrons from them or when
it creates “free radicals” that steal electrons from our proteins and DNA.
Name and identify the different parts of our digestive system (
mouth, stomach, small intestine, pancreas, liver, gall bladder
Food passes from mouth to esophagus to stomach to small intestine. Any material not absorbed by the small
intestine passes to the large intestine then the rectum and out the anus. We all recognize those organs as our
digestive system, BUT I’ve omitted two other organs that are part of the digestive system! Food does NOT
pass through them, but they are essential for the digestion of food in the small intestine, and digestion is
essential for the absorption of molecules that comprise food. Name these two organs.
Liver, Pancreas
In what parts of our digestive system do enzymes carry out chemical digestion?
mouth, stomach, and small intestine
Where does most enzyme-based digestion occur?
Small intestine
Which organ secretes digestive enzymes into the small intestine?
Pancreas
