MCAT Bio Mnemonics

Question 1

What are the two amino acids that form a disulfide bridge? (Ch. 4)

Answer 1

Two cysteines
Mnemonic: Cyestines are like sistas kept apart by the disulfide bridge (covalently bonded)

Question 2

+ RNA viruses must encode: (Ch. 5)

Answer 2

RNA-dependent RNA pol (and do not have to carry it)

Question 3

-RNA viruses must carry: (Ch. 5)

Answer 3

RNA dependent RNA pol (and of course, encode it too)

Question 4

Retroviruses must encode: (Ch. 5)

Answer 4

reverse transcriptase

Question 5

The three main retroviral genes are: (Ch. 5)

Answer 5

gag- codes for viral capsid proteins)
pol- polymerase codes for reverse transcriptase
env- envelope does for viral envelope proteins

Question 6

Double-stranded DNA viruses often encode: (Ch 5)

Answer 6

enzymes required for dNTP synthesis and DNA replication

Question 7

Gram Negative Stain = (Ch. 5)

Answer 7

light pink color (like Mean Girls is negative so it’s pink)
The increased protection of gram-negative bacteria from the environment is reflected in their weak staining and increased resistance to antibiotics due to periplasmic space.

Question 8

Gram Positive Stain = (C. 5)

Answer 8

dark purple
Purple = royalty which is a positive thing

Question 9

What is the periplasmic space in Gram Negative bacteria? (Ch. 5)

Answer 9

It is an intermediate space between the cell membrane and outer layer which sometimes contains enzymes that can degrade antibiotics.

Question 10

Monotrichous flagella means (Ch. 5)

Answer 10

flagellum located at only one end

Question 11

Amphitrichous flagella means (Ch. 5)

Answer 11

flagellum located at both ends.
Amphi = Amphibian like a frog which has 2 legs

Question 12

Peritrochous flagella means (Ch. 5)

Answer 12

multiple flagella

Question 13

Mnemonic for understanding chemotaxis (Ch. 5)

Answer 13

Blind-fold game
where blindfolded person moves randomly but selects favorable or unfavorable movements towards the goal (warmer or colder) like chemoreceptors binding attractant or repellent and sending a signal to the bacteria to tumble or not to tumble.

Question 14

The response of flagellar rotation to chemical attractants or repellants is dependent on an ____ concentration

Answer 14

change in concentration over time. So as bacterium moves through the solution it is able to detect whether it is moving toward or away from the highest concentration and respond accordingly.

Question 15

What is an autotroph? (Ch. 5)

Answer 15

utilize CO2 as their carbon source

Question 16

What is a heterotroph? (ch 5)

Answer 16

rely on organic nutrients (ex glucose) created by other organisms

Question 17

What is a chemotroph? (Ch 5)

Answer 17

get their energy from chemicals

Question 18

What is a phototroph? (Ch 5)

Answer 18

get their energy from light not only plants but some bacteria do this too.

Question 19

What is a chemoautotroph? (Ch 5)

Answer 19

build organic macromolecules from CO2 using the energy of chemicals. They obtain energy by oxidizing inorganic molecules like H2S

Question 20

What is a chemoheterotroph? (Ch 5)

Answer 20

require organic molecules such as glucose made by other organisms as their carbon source and for energy. (Humans are this)

Question 21

What is a photoautotroph? (Ch 5)

Answer 21

use only CO2 as their carbon source and obtain energy from te Sun (plants are this)

Question 22

What is a photoheterotroph? (Ch 5)

Answer 22

are odd in that they get their energy from the Sun, like plants, but require an organic molecule made by another organism as their carbon source.

Question 23

What is an auxotroph? (Ch 5)

Answer 23

this is a bacterium that cannot survive on minimal media because it can’t synthesize the molecule it needs to live. It requires an auxiliary or trophic substance to live.

Question 24

What is respiration? (Ch 5)

Answer 24

glucose catabolism w/ the use of inorganic electron acceptor such as O2

Question 25

What is fermentation? (Ch 5)

Answer 25

glucose catabolism which does not use an electron acceptor such as O2; instead a reduced byproduct of glucose catabolism such as lactate or ethanol is given off as waste

Question 26

What is anaerobic respiration? (Ch 5)

Answer 26

Refers to glucose metabolism w/ ETC and Oxidative phosphorylation by relying on an external electron acceptor other than O2
Example: Nitrate (No3-)

Question 27

It’s cool to be K+ resting in the cell

Answer 27

During resting membrane potential there is a higher concentration of Na+ outside of the cell and a higher concentration of K+ inside of the cell