Mod 3 and Mod 4 :D Flashcards
1
Q
What is the Cell Membrane Structure made up of?
A
Proteins, Lipids, Carbohydrates
2
Q
What is it called when two lipids are layered on top of one another?
A
Phospholipids
3
Q
If the head of a phospholipid is too bulky, forms spheres called?
A
micelles
4
Q
If phospholipid contains a smaller head, forms bilayer that has? and is called?
A
Inner space, called liposomes
5
Q
What impacts the fluidity of membranes?
A
- Length of fatty acid tails. If longer = less fluid, if shorter = more fluid
- Also the presence of carbon-carbon double bonds, with fewer = less fluid, more? = more fluid
- Cholesterol - increase or decrease fluidity depending on temperature
6
Q
Which direction do lipid rafts move?
A
In the plane of the membrane.
7
Q
What are the functions of membrane proteins?
A
Transporters to move ions and molecules, receptors that allow cell to receive signals, enzymes to catalyze chemical reactions in the cell, anchors that attach to other proteins
8
Q
What are the role of centrioles?
A
Have spindle fibres attached to them
9
Q
What is the role of ribosomes?
A
Protein synthesis
10
Q
What is the role of lysosomes?
A
Break down molecules, considered a “wreaking ball”
11
Q
What is the role of Smooth ER?
A
Produce lipids
12
Q
What is the role of Rough ER?
A
Produce proteins
13
Q
What is the role of Golgi Apparatus?
A
Receive materials from vesicles, in charge of proteins and lipids, modify and sort them, and add carbohydrates to them. Then release some molecules through vesicles to the cell membrane
14
Q
What is the difference between animal cells and plant cells?
A
cell wall, chloroplast, centrioles, central vacuole, and mini vacuoles
15
Q
What is the difference and similarities between prokaryotes and eukaryotes?
A
Presence of nucleus, membrane-bound organelles
Both have ribosomes, have genetic material
16
Q
What are vacuoles?
A
Storages for different molecules
17
Q
What is the role of chloroplasts?
A
Light pigmentation - that transfers their colouring to green, photosynthesis, produce glucose
18
Q
What is the role of mitochondria?
A
produce ATP which takes part in cellular respiration
19
Q
What is the fluid mosaic model?
A
Talking about the cell membrane
Fluid - meaning lipid bilayers are fluid, allow molecules to move laterally within the membrane
Mosaic - meaning mixture, mixture of different proteins, lipids, carbohydrates
20
Q
Which molecules are more permeable than others?
A
Gases (O2 and CO2), non-polar molecules (lipids), small uncharged polar molecules (H2O)
21
Q
Which molecules are not as permeable?
A
Macromolecules(proteins, carbohydrates)
22
Q
What is it movement of substance into cells called?
A
Influx
23
Q
What is movement of substances out of cells called?
A
Efflux
24
Q
What is it called when one movement of substances exceeds the other?
A
Net flux
25
There are two mechanisms of passive transport, what are they called?
Simple diffusion and Facilitated diffusion
26
What is Facilitated diffusion?
molecules move down concentration gradient through protein transporter
two types: channel protein, and carrier protein
27
What are channel proteins? (facilitated diffusion)
formed by integral membrane proteins, permeable to selected molecules, exist in open or closed conformation (gated channels)
28
What are carrier proteins?
when specific molecules bind to the protein, and are transporter through it (down concentration gradient!)
29
What is the osmotic pressure? (in osmosis)
tonicity of solution a cell is surrounded by
30
If tonicity of solution is equal on either side of membrane, it is called?
isotonic
31
What are hypertonic solutions?
cell shrinks
animal cells shrivel and die - crenation
plant cells pull away from surrounding cell wall - plasmolysis
32
What are hypotonic solutions?
cell swells
animal cells will burst ( red blood cell) - hemolysis
plant cells will push against surrounding wall - turgor pressure
33
what is the definition of active transport?
movement of substances against the concentration gradient
34
what are the components part of active transport?
uses protein carrier, requires energy, substance binds to transporter and moves against gradient
change conformation upon binding to substance - movement is in one direction
35
what are the two types of active transport called?
primary active transport and secondary active transport
36
what are electrochemical gradients?
more sodium out than in
37
what type of energy does primary and secondary active transporters use?
primary uses chemical energy of ATP directly, whereas secondary uses the electrochemical gradient
38
what are the two types of co-transport?
antiport and symport
39
what is antiport?
two solutes move in opposite direction
40
what is symport?
two solutes move in the same direction
41
what organelle is involved in synthesis of proteins and lipids?
nucleus
42
what organelle modifies proteins and lipids produced by ER, acts as a sorting station?
golgi apparatus
43
what organelle contains enzymes that break down macromolecules such as proteins, nucleic acids, lipids, and complex carbohydrates?
lysosomes
44
what organelle is specailzed that harnesses energy fort eh cell?
mitochondria
45
what organelle contains a protein scaffold that provides cell strucutre?
cytoskeleton
46
a plant cell has many of the same features as an animal cel but also..?
cell wall (provide extra support to the cell), chloroplast (convert energy from sunlight into chemical energy that a cell can use), central vacuole (contribute to structure by maintaining turgor pressure)
47
what is the definition of exocytosis?
process where vesicle fuses with cell membrane known as
48
what is the process of exocytosis?
when vesicle buds off form endomembrane system, fuse with plasma membrane and deliver content into extracellular space
49
what is the definition of endocytosis?
process of material from outside cell brought into vesicle that can fuse with other organelles
50
what is the process of endocystosis?
cell membrane invaginates (pocket around target material), pocket pinch off inside cell (result in material surrounded by newly created intracellular vesicle formed from cell membrane)
51
what are the names of different variations of endocytic processes?
phagocytosis, pinocytosis, receptor-mediated endocytosis
52
what is the short description of phagocytosis?
uptake of particulate matter
53
what is the short description of pinocytosis?
"cell drinking"
54
what is the short description of receptor-mediated endocytosis?
cell membrane receptor proteins have specific binding to certain substances
55
what are the components of endoplasmic reticulum (ER)?
large organelle in most eukaryotic cells, produce many lipids and proteins used inside and outside of cell, in network of interconnected tubules and flattened sacs -> Lumen, highly folded nature allow for large membrane surface area to fit inside the cell
56
what is the rough endoplasmic reticulum (RER) a part of?
ribosome associated with membrane and exposed to cytosol
57
what are the ribosomes in RER important for?
site for protein synthesis - where amino acids are assembled into polypeptides (free from cytosol)
58
what is the smooth ER (SER)?
bud off to produce vesicles that are free to move in the cytosol, site for fatty acid and phospholipid synthesis
59
What is the SER a site of?
fatty acids and phospholipid synthesis, lack ribosomes
60
what is the next step for vesicles that bud off of ER?
golgi apparatus
61
what are the three functions of golgi appratus?
modify proteins and lipids, sort proteins and lipids, add carbohydrates to proteins and lipids
62
what are the flattened sacs that Golgi apparatus consists of?
cisternae
63
what is doing the modifying in golgi apparatus?
enzymes (chemically modify)
64
what is the function of lysosomes?
degrade damage or unneeded macromolecules like proteins, nucleic acids, lipids, and complex carbohydrates
65
what happens with the enzymes found within lysososme?
synthesized in the RER - sorted in the Golgi apparatus - packaged into lysosome
66
what is the specialized proteins in the the lysosome membranes?
proton pump - keep internal pH of lysosome at a 5
67
why is it important to keep contents of lysosome separate from rest of the cell?
because pH of lysosome is 5, organelles and proteins would degrade if exposed to it (as their pH is 7)
68
what are the key two membranous organelles that are not part of the endomembrane system?
mitochondria and chloroplast
69
what is common with both mitochondria and choloroplast?
they are semi-autonomous - grow and multiply independently and contain their own circular genomes
70
what does mitochondria harness their energy from?
chemical compounds, like sugars, and convert them into ATP
71
what are the four parts apart of mitochondria?
outer membrane, intermembrane space, inner membrane, and matrix
72
what is associated with the outer membrane part of the mitochondria?
they contain integral proteins
and porins, that are nonselective membrane channels
73
what is associated with the intermembrane space part of the mitochondria?
contain aqueous compartments between outer and inner membrane
74
what is associated with the inner membrane that is part of the mitochondria?
highly convoluted - electron transport chain and ATP synthase
75
what is associated with the matrix that is part of the mitochondria?
citric acid cycle, ribosomes, and DNA
76
what energy does chloroplast take?
capture sun's energy to synthesize simple sugars, where photosynthesis takes place
77
what is the double membrane that surrounds chloroplast?
thylakoid membrane
78
what is the thylakoid membrane?
contain light-collecting molecules called pigments
chlorophyll is the most common - gives green colour see in many plants
79
what is the chloroplast structure?
thylakoids, lumen, grana, stroma
80
what is the space inside a thylakoid called?
lumen
81
what is the orderly stacks of thylakoids called?
grana
82
what is the space surrounding thylakoids called?
stroma
83
what is the origin of mitochondria?
from endosymbiotic bacteria - proteobacteria
84
what is the origin of chloroplasts?
from endosymbiotic relationship between Cyanobacteria cell engulfed by a eukaryotic cell
85
what are the basic functions of DNA?
store genetic information, copy itself and transmit genetic information to the next generation
86
what are the components of a nucleotide?
five-carbon sugar, base, one or more phosphate group
87
what are the four bases that a nucleotide normally contains?
adenine, guanine, thymine, cytosine
88
what are the double-ring structures?
adenine and guanine
89
what are the single-ring structures?
thymine and cytosine
90
what are double-ring structures called?
purines
91
what are single-ring structures called?
pyrimidines
92
what are the components of a nucleoside?
sugar and a base
93
where is the 5' phosphate group located?
top
94
where is the 3' phosphate group located?
bottom
95
which ' can bases only be added to?
3' end
96
what are two strands that run in opposite directions called?
antiparallel
97
which base does A pair with?
only with T
98
which base does C pair with?
only with G
99
why is there specificity of base pairing?
specificity happens due to hydrogen bonds that form between A and T, C and G
100
what are the two factors that contribute to stability of DNA?
hydrogen bonds, and base stacking
101
why do hydrogen bonds affect the stability of DNA?
weak bonds, but when many contribute to stability of DNA
102
why does base stacking affect the stability of DNA?
affected by interactions between bases on the same strand
103
how do you read orientation of a polymer?
5' to 3'
104
which end can bases be added to?
3' -OH on sugar
105
which direction does DNA grow?
5' to 3' direction
106
bases A and T, and bases G and C are known as?
complementary
107
two strands that run in opposite direction?
antiparallel
108
the outside contours form uneven pair of grooves called?
major and minor grooves
109
what bond forms between A and T and C and G?
hydrogen bonds
110
DNA can be copied in a process known as..?
replication
111
what does the complementary base pairing ensure?
fidelity of DNA replication
112
two strands of original DNA double helix are known as the?
parental strands
113
parental strand serves as template for synthesis of complementary strand, known as the...?
daughter strands
114
what is the definition of central dogma?
DNA is transcribed into RNA, translated into protein
115
in transcription, what is emphasized?
that DNA and RNA use the same language of nucleic acids
116
what is protein synthesis dependent on?
code carried through mRNA
117
what in translation, what is emphasized?
indicate change in language used - from nuclei acids to amino acids
118
___ unit of heredity affecting one or more traits of an organism; the DNA sequence that corresponds to a specific protein
gene
119
______ production of functional gene product, such as protein
gene expression
120
gene's expressed?
turned on
121
genes can be not expressed?
turned off
122
where does transcription and translation occur in prokaryotes?
transcription and translation occur in cytoplasm
123
where does transcription and translation occur in eukaryotes?
transcription occurs in nucleus, and translation occurs in cytoplasm
124
what are the differences of DNA and RNA?
sugar in RNA has hydroxyl (OH) group at 2' carbon and DNA has hydrogen (-H), Uracil replaces thymine, 5' end in RNA is triphosphate and DNA has 5' end in monophosphate, RNA often shorter length has single strand, whereas DNA is double stranded
125
what is the general process of transcription?
copy DNA sequence into RNA sequence
126
what is DNA's role in transcription for RNA?
template for RNA production in cell
127
what is the enzyme needed for transcription?
RNA polymerase
128
which direction is polymerase read along DNA template strand by RNA polymerase?
3' to 5'
129
what provides energy to drive anabolic and synthetic reactions?
ribonucleotide triphosphates
130
where does transcription take place?
from one DNA strand - used as template for RNA transcript
131
what are the three transcription stages?
initiation, elongation, and termination
132
which direction does new RNA strand grow in?
5' to 3' direction
133
what is the initiation stage of transcription in bacteria?
sigma factor, the protein that helps RNA Pol and RNA Pol binding to specific promoters
134
what is initiation stage of transcription in eukaryotes?
general transcription factors, set of 6 proteins bind to promoter region, transcriptional activator proteins bind to enhancer sequence on DNA, recruits RNA polymerase complex RNA Pol ll
135
how is the transcription bubble formed?
looping DNA to bring activator proteins into contact with protein bound at promoter region (initiation of transcription)
136
how does transcription elongation stage occur?
RNA Pol and RNA Pol ll allow for unwinding of DNA, for complementary nucleotides to be added to growing mRNA transcript
137
what are the channels responsible for in transcription elongation stage?
allow for RNA nucleotide triphosphate to enter, DNA double helix, exit for growing mRNA, and release mRNA when transcription is terminated
138
what are the steps for polymerization reaction?
RNA polymersae detect incoming ribonucleoside triphosphate end, base pairs join to expand transcript
139
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