DNA replication/transcript/etc Flashcards Preview

MCAT - Bio/Biochem > DNA replication/transcript/etc > Flashcards

Flashcards in DNA replication/transcript/etc Deck (51):
1

In what ways is transcription similar to DNA replication? And different?

Similarities:
1. "start" site
2. 5'->3' direction
3. DNA template

Differences:
1. "stop" site
2. No primer
3. No editing

2

During transcription, what is another name for the template strand?

Antisense strand
is complementary to the new mRNA

3

During transcription, what is another name for the coding strand?

Sense strand. This is identical to the new mRNA except for U instead of T.

4

What can adenine turn into on tRNA?

Inosine

5

What bases can inosine bind to?

A, U, or C

6

Wobble base pairing occurs when you have a _____ at the 3rd position

G, U, or I

7

Prokaryotic ribosome = ?

50s + 30s = 70s

8

Eukaryotic ribosome = ?

60s + 40s = 80s

9

How many ATP are needed to translate x # of amino acids?

# of amino acids x 4 = # of ATP needed

10

What mnemonic can you use to remember the DNA/protein/RNA assays?

S outhern D NA
N orthern R NA
O O
W estern P rotein

11

What is a complex transposon?

IS element + one or more genes

12

What is a composite transposon?

2 IS elements and an intervening sequence.

13

What does +RNA mean?

mRNA (for viruses)

14

In what phase(s) of meiosis does non-disjunction occur?

Anaphase I and II

15

During meiosis, _________separate during meiosis I, and __________ (identical copies, except for recombination) separate during meiosis II

homologous chromosomes separate during meiosis I and sister chromatids separate during meiosis II

16

What is genetic drift?

Random change over time in the allele frequency within a population

17

What is a prezygotic barrier to hybridization?

Prevent the formation of a zygote

18

What is a postzygotic barrier to hybridization?

When a zygote forms and develops into a functional organism but is incapable of reproduction

19

Most of the voltage-gated sodium channels are concentrated where on the dendrite?

Axon hillock

20

What do Schwann cells do?

Generate myelin sheath

21

What is the resting membrane potential of cells?

-70mV

22

What maintains the resting potential?

Na/K ATPase

(3 Na out, 2 K in) generates a negative internal charge

23

What is "threshold potential" and what happens when the cell reaches it?

Threshold potential is ~-50mV. When it is reached, voltage-gated Na channels open. (Na rushes in and the cell depolarizes).

24

How does the cell repolarize during an AP?

Na channels close and K channels open (K moves out of the cell)

25

How are neurotransmitters released at the end of an axon?

Voltage-gated Ca channels open, releasing the brakes on neuro-transmitter filled vesicles, allowing the vesicles to fuse with the membrane and dump the contents into the synaptic cleft.

26

What is an EPSP?

A mini-depolarization that does not reach threshold--ultimately has no effect.

27

What is spatial summation?

Summation of excitatory and inhibitory signals on a neuron

28

What is temporal summation?

Summation of an excitatory/inhibitory signal over some time period. The most frequently firing neuron will be "heard the most loudly."

29

What does the medulla do?

Basic vital functions
Special respiratory and digestive functions

30

What does the pons do?

Balance
Facial movement

31

What does the spinal cord do?

Primitive reflexes

32

What does the cerebellum do?

Smooth and coordinate body movement

33

What does the midbrain do?

Visual and auditory startle reflexes

34

What does the limbic system do?

Emotion

35

What is the diencephalon?

Contains

epithalamus
thalamus
hypothalamus

36

What does the epithalamus do?

Contains the pineal gland--secretes melatonin

37

What does the white matter contain? What does it do?

Myelinated axons
Cell-cell comunication

38

What is grey matter? What does it do?

Unmyelinated dendrites and somas.
Integration, decision-making

39

What do the frontal lobes do/control?

Voluntary movements
Problem-solving

40

What does the parietal lobe do?

General sensation - touch, taste, etc.

41

What does the temporal lobe do?

Hearing
Smell
Memories

42

What neurotransmitter does the somatic nervous system use?

Acetylcholine

43

What neurotransmitters does the autonomic nervous system use?

Norepinephrine (Sympathetic)
Acetylcholine (Parasympathetic)

44

What is unique about the default/resting state of rod and cone cells?

Na channels are OPEN, and thus they sit in a resting depolarized state.

45

How does light affect the vision cells?

Light causes release of an inhibitory neurotransmitter inhibiting the bipolar neuron, and allowing signal to brain.

46

What is another name for the ear drum?

Tympanic membrane

47

What are the three bones of the inner ear?

Malleus -> incus -> stapes

48

What connects the bones of the ear to the cochlea?

The oval window

49

Waves in the _______ and __________ in the ________ cause the ___________ to vibrate.

Waves in the endolymph and perilymph in the cochlea cause the basilar membrane to vibrate

50

Where do the hair cells exist?

Above the basilar membrane and below the tectorial membrane. Vibration of the basilar membrane drags hair cells across the tectorial membrane causing them to bend.

51

What are the 4 components of the vestibular complex?

1. Semicircular canals (rotational balance)
2. Saccule
3. Utricle
4. Ampulla

2-4 = static balance