lecture 5&6 Flashcards

1
Q

what is the purpose of nucleic acids

A

store and transmit genes
program amino acid sequence of polypeptide (proteins)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

structure of nucleic acids

A

made of nucleotides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what are the two types of nucleic acids

A

deoxyribonucleic acid (dna)
ribonucleic acid (rna)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what does the dna do

A

stores information for protein synthesis
acts as a blueprint to make the proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what does the rna do

A

directs protein synthesis
acts as messenger to relay information from dna

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what replaces thymine in rna

A

uracil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is the structure of nucleic acids

A

a phosphate molecule
a 5 carbon sugar
a nitrogenous base

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what sugars do dna and rna have

A

dna has deoxyribose
rna has ribose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what kind of formation do the dna strands have

A

antiparallel formation
3 prime to 5 prime

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what are the functions of histones

A

wind the dna to fit 2m into 10 nanometers of space
control gene activation and deactivation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what do gene have to do with proteins

A

genes have the information needed to make the specific protein and the primary sequence of the protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what are the two major steps in protein synthesis

A

transcription
translation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what are the steps of transcription

A
  1. separation of dna at a particular gene
  2. synthesis of mRNA (using uracil)
  3. mRNA is sent to cytosol
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is the start codon of transcription

A

AUG

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

do the start/stop codon code for amino acids

A

only the start codon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what are codons

A

group of three nucleotides that code for one amino acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what are the characteristics of mRNA

A

single stranded
synthesized in nucleus with the help of enzymes and dna
has the information of one gene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is translation

A

the assembly of the protein’s primary structure according to the codon sequence on the mRNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what does the tRNA do

A

decode the codons of mRNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

how does the tRNA work

A

it has anti codons that complementary bind to the mRNA codons while creating an amino acid chain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

how many codons are there

A

64 (1 start, 3 stop and 61 amino acids)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

how many anticodons are there

A

31 (many codons code for the same amino acid)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what does the rRNA do

A

links mRNA and tRNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what is the structure of rRNA

A

3 tRNA binding sites:
1. A site (aminoacyl-tRNA)
2. P site (peptidyl-tRNA)
3. E site (exit site)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

what is the process of translation

A

tRNA attaches to the start codon at the P site
the next tRNA attaches to the A site
the ribosome moves along the mRNA which makes the tRNA leave through the exit site
this builds the amino acid chain until the stop codon is reached

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

when the stop codon is reached what happens

A

a release factor binds to the A site which causes a water molecule to be added to hydrolysis the chain
this releases the polypeptide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

what is the range of cell size*

A

8 to 100 um

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

why are cells so small*

A

because as cell size increase the metabolic needs of the cell increases
the surface area is smaller than the volume so it can’t meet the demands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

what does having a smaller volume mean for a cell*

A

less metabolic demands but also less surface area to transport materials in and out

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

what is the range of size for prokaryotic cells*

A

1-10 um

31
Q

how do you classify organisms in the bacteria domain*

A

using the gram test

32
Q

what are characteristics of gram positive bacteria*

A

stain blue/purple
have a thick peptidoglycan layer after the plasma membrane

33
Q

what are the characteristics of a gram negative bacteria*

A

stain red
have a thin peptidoglycan layer
have an extra outer membrane

34
Q

what are the functions of cell walls*

A

rigidity
protection from bursting

35
Q

do antibiotics have a harder time going through gram + or - bacteria*

A

gram - (extra outer membrane)

36
Q

what are the functions of capsule on prokaryotes*

A

prevents the cell drying
helps cell stick to things
protects cell from white blood cells (no antigens so w.b.c. can’t recognize it as enemy)

37
Q

what are three characteristics of the domain archaea*

A

have histones (proteins) associated with dna like eukaryotic cells
have s layer on cell surface
have a cell wall (no peptidoglycan)

38
Q

what is the s layer on archaea composed of*

A

glycosylated proteins (have glucose)

39
Q

what are the two major categories of organelles*

A

membranous organelles
non membranous organelles

40
Q

examples of membranous organelles*

A

plasma membrane, cytoplasm, nucleus
smooth and rough ER, golgi, vesicles, lysosomes, peroxisome, mitochondria, chloroplast, vacuoles

41
Q

examples of non membranous components*

A

nucleolus, ribosomes, cytoskeleton, centrosome, cilia, flagella, cell junctions, cell wall, extracellular matrix

42
Q

why do we need the plasma membrane*

A

to regulate movement in and out of the cell
the maintain the interior environment balanced (critical for cell processes and function)

43
Q

what are the functions of the plasma membrane*

A

cell adhesion, recognition, communication and regulating interior env.

44
Q

what is the plasma membrane made of*

A

phospholipid molecules
protein molecules
cholesterol

45
Q

what do phospholipids do in the plasma membrane*

A

selectively permeable
allows some substances to cross it better than others

46
Q

what is the fluid mosaic model*

A

proteins moving sideways through the plasma membrane’s bilayer

47
Q

what is the difference between the cytoplasm and the cytosol*

A

cytoplasm is the region between the nucleus and the plasma membrane
cytosol is the fluid substance inside the cell which contains the organelles

48
Q

is the nucleolus membrane bound*

A

no (its inside the nucleus and makes the ribosomes)

49
Q

what does the membrane of the nucleus look like*

A

looks like a double membrane but is actually folded over itself (nuclear envelope)
has pores to allow exchange of materials

50
Q

what is a chromatin*

A

loosely arranged dna and protein

51
Q

what is a chromosome*

A

tightly packed dna and histones (proteins) in x shape (46 chromosomes total)

52
Q

what are the two types of endoplasmic reticulum and what makes them different*

A

rough ER (has ribosomes/dots)
smooth ER

53
Q

what is the ER membrane made of*

A

continuation of nuclear envelope
weaves in sheets

54
Q

what are cisternae*

A

tubules and sacs (lipid bilayer) of the ER membrane

55
Q

what are the functions of the rough ER*

A

produce proteins (ribosomes)
distribute proteins to other cells or organelles
modify proteins

56
Q

where does the rough ER send most of its proteins*

A

golgi apparatus

57
Q

how does the rough ER modify proteins*

A

fold into 3D shape
enzyme can modify proteins by adding carbs or lipids to them

58
Q

what are the functions of the smooth ER*

A

synthesize and transport proteins
enzymes detoxify poisons and drugs (liver)
metabolizes carbs
storage of calcium

59
Q

what are the functions of the golgi apparatus*

A

packaging and shipping centre of molecules
chemical modification of molecules
synthesizes carbs

60
Q

characteristics of golgi apparatus*

A

structurally similar to ER
5-20 membranous sacs (cisternae)

61
Q

what is a vesicle*

A

a hollow sphere with a membrane identical to the plasma membrane

62
Q

what is the function of vesicles*

A

store/transport chemicals around the cell

63
Q

what are the two types of vesicles, who makes them and where do they go*

A

transport (ER makes it to get proteins to golgi)
secretory (golgi makes it to go to the plasma membrane or around the cell)

64
Q

what is the function of a lysosome and who makes them*

A

destroy pathogens and damaged organelles
golgi makes them

65
Q

how does a lysosome work*

A

its a vesicle that contains digestive enzymes (pH 5 so acidic) which are only active inside its membrane to prevent damaging the cell in case of leakage (cells pH is 7.2)

66
Q

what are the processes lysosomes go through called*

A

phagocytosis
autophagy

67
Q

what is phagocytosis*

A

lysosome digesting materials from outside the cell

68
Q

what is autophagy*

A

lysosome digesting organelles from inside the cell (itself)

69
Q

how do lysosome digest things*

A

engulfs them

70
Q

what are the functions of peroxisomes*

A

fatty acid metabolism
detoxify harmful compounds (liver)
gets rid of the hydrogen peroxide released when enzymes transfer hydrogen to oxygen (ex. phagocytosis and autophagy)

71
Q

what allows peroxisome to detoxify hydrogen peroxide*

A

has enzyme that turns H2O2 to water

72
Q

what are the functions of mitochondria*

A

power house of the cell
aerobic respiration
makes ATP from glucose

73
Q

how many membranes do mitochondrias have and what are they made of*

A

2 membranes that each have a phospholipid bilayer

74
Q

what is the endosymbiont theory*

A

theory that millions of years ago a cell engulfed another and developed a symbiotic relationship instead of digesting it (believed to have happened with mitochondria and chloroplast because they have the basic structure of a cell)