Chapter 3 Part 1 Lecture Flashcards
1
Q
The purpose of the chapter is to:
A
- Introduce the parts of a cell
- Discuss the importance of the plasma membrane
- Discuss the components of the cytoplasm
- Compare and contrast mitosis and meiosis
- Understand the effects aging has on the cell
2
Q
The cell can be subdivided into 3 parts:
A
- Plasma (cell) membrane
- Cytoplasm
- Nucleus
3
Q
2 things the cytoplasm contains:
A
- cytosol
- organelles
4
Q
2 things in the Nucleus
A
- Chromosomes
- Genes
5
Q
The plasma membrane is a _____ yet ____ barrier that surrounds and contains the cytoplasm of the cell
A
The plasma membrane is a flexible yet sturdy barrier that surrounds and contains the cytoplasm of the cell
6
Q
2 types of membrane proteins are:
A
2 types of membrane proteins are:
- Integral (also called transmembrane) proteins
- Peripheral proteins
7
Q
Integral proteins AKA
A
Transmembrane proteins
8
Q
Membrane proteins can serve a _____of functions
A
Membrane proteins can serve a variety of functions
9
Q
The different proteins help determine many of the ____ of the cell membrane
A
The different proteins help determine many of the functions of the cell membrane
10
Q
Ion channel; Integral or peripheral?
A
- Forms a pore through which a specific ion can flow across membranes
- Integral
11
Q
Carrier; Integral or peripheral?
A
- Transport specific substance across membrane by undergoing change in shape
- Integral
12
Q
Receptor; Integral or peripheral?
A
-Recognizes specific ligand and alter’s cell’s function
13
Q
Example of Carrier/transmembrane protein:
A
Amino Acids: needed to synthesize new proteins and enter body cells through carriers/transporters
14
Q
Example of receptor protein:
A
Antidiuretic hormone: binds to receptors in kidneys and changes water permeability of certain membranes
15
Q
Enzyme; Integral or peripheral?
A
- Catalyzes reactions inside or outside cell depending on which direction active site faces
- Integral and peripheral
16
Q
Linker; Integral or peripheral?
A
- Anchor filaments inside and outside plasma membrane provide structure and shape
- Integral and peripheral
17
Q
Example of enzyme protein:
A
Lactase: protrudes form epithelial cells lining small intestine that splits the disaccharide lactose in the milk you drink
18
Q
Cell identity marker; Integral or peripheral?
A
- distinguishes your cell from anyone else’s
- MHC (major histocompatibility proteins)
19
Q
Membranes are fluid structures because
A
membrane lipids and many of the membrane proteins move easily in the bilayer
20
Q
Membrane lipids and proteins are mobile…
A
…Membrane lipids and proteins are mobile in their own half of the bilayer
21
Q
Cholesterol serves to ______the membrane and reduce membrane fluidity
A
Cholesterol serves to stabilize the membrane and reduce membrane fluidity
22
Q
The lipid bilayer is always permeable to ___ , ___ -____ , ___ -____ molecules
A
The lipid bilayer is always permeable to small, nonpolar, uncharged molecules
23
Q
Transmembrane proteins that act as channels or transporters increase
A
Transmembrane proteins that act as channels or transporters increase the permeability of the membrane
24
Q
Macromolecules are only able to pass through the plasma membrane by ____ _____
A
Macromolecules are only able to pass through the plasma membrane by vesicular transport
25
A concentration gradient is
the difference in the concentration of a chemical between one side of the plasma membrane and the other
26
An electrical gradient is
the difference in concentration of ions between one side of the plasma membrane and the other
27
A concentration gradient + electrical gradient =
electrochemical gradient
28
Transport processes do what?
move substances across the cell membrane
29
3 Passive processes:
- Simple diffusion
- Facilitated diffusion
- Osmosis
30
2 Active processes:
- primary and secondary support
| - vesicular transport
31
Simple diffusion is:
-gradient movement
32
Facilitated diffusion is for which molecules? How is it assisted?
- objects too polar or have a charge charged
| - assisted by integral proteins
33
Osmosis is movement of solvent or solute?
Solvent
34
5 things diffusion is influenced by:
```
-steepness of concentration
gradient
-temperature
-mass of diffusion substance
-surface area
-diffusion distance
```
35
Example of steepness affecting diffusion:
- 20 : 5 vs 100 : 5
| - higher the ratio the faster diffusion will occur
36
How temperature affects diffusion:
- higher temperature=quicker diffusion
| - particles move quicker when warm
37
How mass affects diffusion:
-Something of greater mass may move slower
38
How surface area affects diffusion:
-if a cell has more surface area, there's more room for a molecule to pass through
39
How diffusion distance affects diffusion: (3)
- How far spread out are molecules
- distance to physically move
- Thickness of membrane
40
How does hot and cold air interact?
-With an open fridge and hot room, hot air moves into the fridge. Cold air doesn't move out
41
Transmembrane proteins help solutes that:
Transmembrane proteins help solutes that are too polar or too highly charged move through the lipid bilayer
42
2 types of facilitated diffusion:
- channel mediated
| - carrier mediated
43
osmosis is:
The movement of solvent through a selectively permeable membrane from an area of high concentration to low concentration
44
Tonicity of a solution relates to how:
how the solution influences the shape of body cells
45
Shape of a cell in isotonic solution:
Normal RBC shape
46
Shape of a cell in hypotonic solution:
- Swollen cell
| - It could burst: hemolysis
47
Shape of a cell in hypertonic solution:
- shrunken and spikey cell
| - Spikey: crenation
48
Primary active transport:
- Energy derived from ATP
- changes the shape of a transporter protein which pumps a substance across a plasma membrane against concentration gradient
49
During primary active transport, why does ATP split?
energy created from splitting of the phosphate from ATP enables the protein to change shape
50
2 parts atp splits into in a sodium potassium pump
- phosphate
| - adp
51
What happens to the Na after the atp is split and protein channel changes shape?
The Na leaves to the outside
52
What happens when the two potassium ions bind during primary transport?
When the potassium binds, the phosphate leaves
53
What happens when potassium binds and phosphate leaves?
The heart ion channel changes back to the upside down heart and K+ is moved into the cell
54
End result of a sodium potassium pump:
-Na is out of the cell and K is inside of the cell
55
How does secondary use ATP and how does it differ form primary transport? (2)
- technically active because it can do transportation because of atp
- but mechanism doesnt use atp; uses it indirectly
56
2 types of transport in vesicles?
-Exocytosis
| =Transcytosis
57
Exocytosis –
membrane-enclosed secretory vesicles fuse with the plasma membrane and release their contents into the extracellular fluid
58
Transcytosis –
- a combination of endocytosis and exocytosis
| - used to move substances from one side of a cell, across it, and out the other side (IN ACROSS & OUT)
59
Passive process official: (2)
- Movement of substances down a concentration gradient until equilibrium
- do not require cellular energy in the form of ATP.
60
Diffusion process official:
-Movement of molecules or ions down a concentration gradient due to their kinetic energy until equilibrium.
61
Simple diffusion official:
Passive movement of a substance down its concentration gradient through the lipid bilayer of the plasma membrane without the help of membrane transport
proteins.
62
Facilitated diffusion official:
Passive movement of a substance down its concentration gradient through lipid bilayer by transmembrane proteins as channels or carriers
63
What does simple diffusion transport? (2)
- Nonpolar hydrophobic solutes
| - polar molecultes like water
64
What does facilitated diffusion transport?
- polar or charged solutes
| - ions like K+ or Na+
65
Osmosis official:
Passive movement of water molecules across selectively permeable membrane from area of higher to lower water concentration until equilibrium
66
Active processes official: (2)
Movement of substances against a concentration gradient; requires cellular energy in the form of ATP.
67
Active transport official:
-Active process in which a cell expends energy to move a substance across the membrane against its concentration gradient by transmembrane proteins that function as carriers.
68
What does osmosis transport?
Water in living systems
69
What does active processes and active transport, transport?
-polar or charged solutes
70
Primary active transport official:
Active process in which a substance moves across the membrane against its concentration gradient by pumps (carriers) that use energy supplied by hydrolysis of ATP.
71
Secondary active transport official:
Coupled active transport of two substances across the membrane using energy supplied by a Na+ or H+ concentration gradient maintained by primary active transport pumps.
72
Substances transported through primary active transport:
ca2+ , H+ and other ions
73
Substances transported through secondary active transport: (2)
- Antiport: Ca2+ , H+ out of cells
| - Symport: glucose , amino acids into cells
74
Antiporter process:
Antiporters move Na+ (or H+) and another substance in opposite directions across the membrane
75
Symporter process:
symporters move Na+ (or H+) and another substance in the same direction across the membrane.
76
Transport in vesicles official: (2)
- Active process in which substances move into or out of cells in vesicles that bud from plasma membrane
- requires energy supplied by ATP.
77
Endocytosis
Movement of substances into a cell in vesicles.
78
Receptor-mediated endocytosis
Ligand-receptor complexes trigger infolding of a clathrin-coated pit that forms a vesicle containing ligands.
79
5 things receptor-mediated endocytosis transports:
- transferrin
- Low-density lipoproteins (LDL)
- vitamins
- certain hormones
- antibodies
80
Phagocytosis AKA
cell-eating
81
Phagocytosis:
-movement of a solid particle into a cell after pseudopods engulf it to form a phagosome
82
3 substances transported by phagocytosis:
- bacteria
- viruses
- aged or dead cells
83
Bulk-phase endocytosis AKA
cell-drinking
84
Bulk phase endocytosis:
-movement of extracellular fluid into a cell by infolding of plasma membrane to form a vesicle
85
Exocytosis
-Movement of substances out of a cell in secretory vesicles that fuse with the plasma membrane and release their contents into the extracellular fluid.
86
3 substances transported by exocytosis:
- neurotransmitters
- hormones
- digestive enzymes
87
Transcytosis:
-Movement of a substance through a cell as a result of endocytosis on one side and exocytosis on the other
88
Example of transcytosis: (2)
- antibodies across endothelial cells
| - common route for substances to pass between blood plasma and interstitial fluid
89
How many components does cytoplasm have?
2
90
Cytosol: AKA
intracellular fluid portion of cytoplasm
91
Organelles in cytoplasm:
specialized structures that have specific shapes and functions
92
Plasma membrane description:
-Fluid mosaic lipid bilayer studded with proteins; surrounds cytoplasm.
93
3 layers in a fluid mosaic lipid bilayer?
- phospholipids
- cholesterol
- glycolipids
94
Plasma membrane functions:
- protects cellular contents
- make contact with other cells
- mediates entry and exit of substances
95
6 components a plasma membrane contains:
- channels
- transporters/carriers
- receptors
- enzymes
- linkers
- cell identity markers
96
Cytoplasm description: (2)
- Cellular contents between plasma membrane and nucleus
| - cytosol and organelles.
97
cytoplasm funciton:
-Site of all intracellular activities except those occurring in the nucleus.
98
Cytosol description and composition: (5)
- water
- solutes
- suspended particles
- lipid droplets
- glycogen granules
99
Cytosol function:
-fluid in which many of cell's metabolic reactions occur
100
Cytoskeleton description and composition: (2)
Composed of three protein filaments:
- microfilaments
- microtubules
- intermediate filaments
101
2 cytoskeleton functions:
- maintains shape and general organization of cellular contents
- responsible for cell movements
102
Organelle description:
Specialized structures with characteristic shapes.
103
Organelle function:
Each organelle has specific functions.
104
Centrosome description:
Pair of centrioles plus pericentriolar matrix.
105
Centrosome functions:
The pericentriolar matrix contains tubulins, which are used for growth of the mitotic spindle and microtubule formation.
106
Cillia and flagella description:
Motile cell surface projections that contain 20 microtubules and a basal body.
107
Cillia function:
move fluids over cell's surface
108
Flagella function:
move entire cell.
109
Ribosome description: (2)
- Composed of two subunits containing ribosomal RNA and proteins
- may be free in cytosol or attached to rough ER.
110
Ribosome function:
Protein synthesis
111
Endoplasmic reticulum description:
Membranous network of flattened sacs or tubules.
112
Rough ER description: (2)
- rough ER is covered by ribosomes
| - attached to the nuclear envelope
113
Smooth ER description:
smooth ER lacks ribosomes.
114
Rough ER functions: (3)
synthesizes glycoproteins and phospholipids that are
- transferred to cellular organelles
- inserted into plasma membrane or
- secreted during exocytosis
115
Smooth ER functions: (4)
- synthesizes fatty acids and steroids
- inactivates or detoxifies drugs
- removes phosphate group from glucose-6-phosphate
- stores and releases calcium ions in muscle cells
116
Golgi complex description and composition: (2)
- Consists of 3-20 flattened membranous sacs called cisternae
- structurally and functionally divided into entry (cis) face, medial cisternae, and exit (trans) face
117
Entry (cis) face functions:
face accepts proteins from rough ER
118
(3) medial cisternae functions:
form
- glycoproteins
- glycolipids
- lipoproteins
119
(2) exit (trans) face functions:
- modifies molecules further,
| - then sorts and packages them for transport to their destinations.
120
Lysosome description and composition:
- Vesicle formed from Golgi complex
| - contains digestive enzymes
121
4 lysosome functions:
-Fuses with and digests contents of
-endosomes
-phagosomes
-vesicles
formed during bulk-phase endocytosis
-transports final products of digestion into cytosol
-digests worn-out organelles
-digests entire cells and extracellular materials.
122
Lysosome autophagy:
Lysosomes digests worn out organelles
123
Lysosome autolysis 2 steps:
- lysosome digests entire cells
| - destruction of sick or injured cells through release of lysosome enzymes
124
(3) peroxisome description:
- structures similar in shape to lysosomes but smaller
- Vesicle containing oxidases and catalase
- new peroxisomes bud from preexisting ones.
125
Oxidases AKA
oxidative enzymes
126
Catalase function:
decomposes hydrogen peroxide
127
(2) peroxisome functions:
- uses oxygen to oxidize or break down organic substances like amino acids and fatty acids
- detoxifies harmful substances (hydrogen peroxide and free radicals)
128
Proteasome description:
Tiny barrel-shaped structure that contains proteases
129
Proteases AKA
Protealytic enzymes
130
3 proteasome functions:
```
Degrades
-unneeded
-damaged
-faulty proteins
by cutting them into small peptides.
```
131
(3) mitochondrion composition and description:
- external and an internal mitochondrial membrane
- cristae, and matrix
- new mitochondria form from preexisting ones.
132
Mitochondrion functions:
- Site of aerobic cellular respiration reactions that produce most of a cell's ATP
- Plays an important early role in apoptosis.
133
What plays an important (early) role in Apoptosis?
Mitochondrion
134
Nucleus components and description:
Consists of a
- nuclear envelope with pores
- nucleoli
- chromosomes, which exist as a tangled mass of chromatin in interphase cells.
135
How do chromosomes exist in interphase cells?
As a tangled mass of chromatin
136
function of nuclear pores in nucleus control:
the movement of substances between nucleus and cytoplasm
137
function of nucleoli in nucleus produce:
ribosomes
138
(2) function of chromosomes in nucleus consist:
of genes that
- control cellular structure
- direct cellular functions
139
Where do proteins in membrane vesicles go from the golgi complex"
They merge with the plasma membrane
140
What does the nucleus contain and how is it arranged?
- contains hereditary units of cells called genes
| - genes are arranged along chromosomes
141
2 steps of gene expression:
- Transcription
| - Translation
142
Where does transcription occur?
in the nucleus
143
Transcription process is:
the process by which genetic information encoded in DNA is copied onto a strand of RNA to direct protein synthesis
144
Where does translation occur:
Translation occurs in the cytoplasm
145
Translation process is:
the process of reading the mRNA nucleotide sequence to determine the amino acid sequence of the newly formed protein
146
Messenger or mRNA
-directs synthesis of a protein
147
Ribosomal or rRNA
-joins with ribosomal proteins to make ribosomes
148
Transfer or tRNA binds to:
-binds to an amino acid and holds it in place on a ribosome until incorporated into a protein during translation
149
Two ends of the tRNA:
- first end carries a specific amino acid
| - second end consists of a triplet of nucleotides called anticodon
150
What happens by pairing between complementary bases in tRNA?
the tRNA anticodon attaches to mRNA codon by pairing between complementary bases
151
The 20 different types of tRNA all bind to
one specific of the 20 different amino acids
152
7 protein synthesis steps
1. initiator tRNA attaches to start codon
2. large and small ribosomal subunits form functional ribosome and initiator tRNA fits into P site
3. Anticodon of incoming tRNA pairs with next mRNA codon at A site
4. Amino acid on tRNA at P site will form peptide bond with amino acid at A site
5. Two peptide protein from peptide bond becomes attached to tRNA at A site
6. Ribosome shifts by one codon (left): tRNA at P site goes to E site and is released from ribosome while tRNA at A site moves to middle P site
7. protein synthesis stops when ribosome reaches stop codon on mRNA sequence
