BIOL 121 Lecture Notes - Lecture 3: Genetic Code, Ectoderm, Endoderm
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Value: 1
Anabolic pathways of metabolism are pathways that:
a. build complex molecules from simple ones.
b. release stored chemical energy.
c. take place primarily in skeletal muscle
d. make large quantities of ATP.
Value: 2
The sum of all chemical reactions in a cell is referred to as _______________.
Value: 3
Organisms that derive both their energy and carbon from organic compounds are:
a. photoautotrophs.
b. chemoautotrophs.
c. chemoheterotrophs.
d. photoheterotrophs
Value: 4
It is often stated that the phosphate bonds in ATP are "high energy," but in fact, they are not notably high in energy. Rather, they are easy to break, and the âG of hydrolysis is a "useful" quantity of energy. What makes the phosphate bonds easy to break?
a. They are close to the destabilizing nitrogenous base adenosine
b. Positive charges on amino groups repel each other.
c. Negative charges on phosphate groups repel each other
d. High acidity attacks bonds between amino acids.
Value: 5
Which of the following describes ATP hydrolysis? Select all that apply
[mark all correct answers]
a. exergonic
b. spontaneous
c. often coupled to a reaction that has a positive ÎG
Value: 6
Which of the following describes catabolic reactions?
a. They are endergonic and have a negative change in free energy
b. They are exergonic and have a negative change in free energy
c. They are exergonic and have a positive change in free energy.
d. They are endergonic and have a positive change in free energy.
Value: 7
Why are cells not infinitely big?
a. Because they wouldn't fit in an organism
b. Because they would have a small surface area:volume ratio and substances would diffuse in and out too slowly
c. Because they would have a large surface area to volume ratio and substances would diffuse in and out too quickly
Value: 9
How is organelle movement around cells controlled?
a. the nucleus directs the movement of organelles in a cell
b. the cytoskeleton is like a monorail that moves organelles in a cell via motor proteins
c. organelles do not move, they have a fixed position in the cell
d. organelles move by facilitated diffusion in the cell
Value: 10
1. Prokaryotic cells lack:
a. a. A nucleus
b. organelles
c. cell membrane
d. DNA
e. A and B
Value: 11
Rough endoplasmic reticulum (rER)
a. a. Makes cell membranes
b. has ribosomes attached
c. are a site of protein synthesis
d. all of the above
Value: 12
Match the items.
The task is to match the lettered items with the correct numbered items. Appearing below is a list of lettered items. Following that is a list of numbered items. Each numbered item is followed by a drop-down. Select the letter in the drop down that best matches the numbered item with the lettered alternatives.
a. help to digest worn-out or damaged organelles. | |
b. Takes in molecules in transport vesicles, modifies them, and sends them back out in vesicles | |
c. makes sugar | |
d. makes ATP | |
e. assembles the ribosomes | |
f. gives the cell structure | |
g. move material around the cell | |
1. vesicles | a b c d e f g |
2. cytoskeleton | a b c d e f g |
3. the golgi apparatus | a b c d e f g |
4. lysosomes | a b c d e f g |
5. mitochondrion | a b c d e f g |
6. chloroplast | a b c d e f g |
7. nucleolus |
I need help on this microbiology question:
Contrary to our favorite science fiction books and movies, the chances of us finding another planet with a civilization comparable to, or even more advanced than our own, seems highly unlikely. But, through your work as a microbiologist at NASA, you have been able to help change our views as to what forms of life we should be looking for on planets in our solar system and around neighboring stars. Instead of radio signals or errant transmissions, we have begun looking for planets that have environments similar to those capable of sustaining life as we know it here on Earth. To determine what we could find out there, you have begun studying different unique and atypical environments found here on Earth. Although the harsh conditions of hot springs or undersea sulfur vents seem incompatible with most forms of life, organisms known collectively as "extremophiles" have still managed to survive and adapt to these extreme conditions. You believe extremophiles may help you gain insight into the potential metabolic requirements, processes, and challenges of extraterrestrial life. Thus far in your search, you have identified some prokaryotic cells that have evolved to survive in the extreme conditions of sulfur vents on the sea floor. These vents are found at great depths, where the crushing pressure and lack of light and oxygen are prohibitive to many forms of life. Bacteria that are not considered extremophiles reside in most ecological niches on this planet. There are some common criteria for the environment that would sustain these bacteria. Availability of water, pH that lies between 5 and 9, temperatures that will remain steady and below boiling; these are some of the characteristics that bacteria will require in their environment if they are to succeed. But in the environment of the ocean floor vents, not only is the pH of the water very low, but also the water temperature is unusually high due to the geologic activity that fuels the vents. Organisms that are adapted to such harsh conditions have necessarily evolved enzymes able to function beyond average optima, as well as a chemosynthetic metabolism capable of using vent organic and inorganic compounds as energy sources.
Part A - Comparable Earth Environments to Be Found on Another Planet
You identify the prokaryotic cells you've found as a species of bacteria. These bacteria appear to be living off of nutrients and sulfur compounds released from the vents on the sea floor. Over time, the bacteria must have evolved extreme metabolic and enzymatic capabilities to allow them to tolerate and even benefit from the extreme depths, the lack of oxygen, the low pH of the surrounding waters, high temperatures due to volcanic releases, and the unique nutrient source of the vents.
Choose the characteristics and their impact on enzyme activity that are not correct from the following statements. (more than one may be chosen)
Archaea are able to tolerate highly acidic pH environments and have proteins that will not denature in the low-pH environments that the bacteria are found in. |
Archaea are able to colonize water that is at or above the boiling temperature due to high levels of disulfide bridges that maintain the three-dimensional structure of the enzyme. |
Archaea are only able to survive exceedingly well at high temperatures due to the amount of activation energy required by their enzymes. |
Archaea are able to grow in extremely shady or low-light conditions that allow for optimal enzyme activity. |