Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Fundamentals Of Medicine: Exam 1 > Organelles I > Flashcards

Organelles I Flashcards

1
Q

[ ] allows cells to spatially organize their activities via [ ].

A

Membranes, selective permeability

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

Which molecules pass through the cell membrane easier?

A
  1. Hydrophobic molecules: O2, CO2, N2
  2. Small uncharged polar molecules: H2O, glycerol, urea, ethanol
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Which type of molecules do not pass through the cell membrane very easy?

A
  1. Large uncharged polar molecules: glucose, sucrose
  2. Ions: Na+, K+, Cl-,
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the key building block of cell membranes?

A

Phospholipids

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

Define amphipathic

A

Both polar and nonpolar qualities

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

What is the hydrophilic, polar part of a phospholipid?

A

The head is polar and hydrophilic due to a phosphate group. The head also contains a glycerol.

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

What is the hydrophobic, nonpolar part of a phospholipid?

A

Fatty acid chains

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

In the aqueous environment of the cell, phospholipids assemble into the [. ] composed of two [. ]

A

Lipid bilayer, leaflets

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

Phospholipids exhibit mobility, what actions are spontaneous versus non-spontaneous?

A

Spontaneous: rotation, lateral diffusion, flexion, rotation
Non-spontaneous: flip between bilayer leaflets

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

Three major groups of membrane proteins:

A
  1. Receptors
  2. Transporters
  3. Enzymes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

[ ] leaflet faces the cytoplasm.

A

Cytosolic

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

[ ] leaflet faces either the lumen of an organelle (if it is part of an organelle membrane) or the extra cellular environment (if it is part of the plasma membrane).

A

Non cytosolic

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

The [ ] of an organelle is topologically equivalent to the outside of the cell.

A

Lumen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What parts of a cell form an extensive bi-directional membrane flow?

A

Endoplasmic reticulum, Golgi apparatus, and lysosomes with the plasma membrane. They are all membrane bound organelles.

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

Topology of membranes is maintained through [ ].

A

Transport vesicles, maintain the membrane lipid and protein orientation

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

4 major types of phospholipids

A
  1. Phosphatidylserine
  2. Phosphatidylcholine
  3. Phosphatidylethanolamine
  4. Sphingomyelin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Is phosphatidylserine mainly found in the cytosolic or non cytosolic leaflet?
What are its main functions?

A

The cytosolic due to its negative charge. functions include apoptosis and blood clotting

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

[ ] is enriched in lipid rafts, can be glycosylated to form glycolipids

A

Sphingomyelin

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

Sphingomyelin is concentrated on the [ ] leaflet

A

Non cytosolic leaflet (extra cellular space, outside of the cell)

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

Define ganglioside

A

The most complex glycolipid formed from a Sphingomyelin phospholipid. Prominently expressed in neurons. Overaccumulation results in highly toxic neurons resulting in a number of diseases

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

Cholera gets in to the cell by interacting with [ ].

A

Ganglioside GM1

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

______ interacts with the fatty acid tails of phospholipids and modulates the bilayer characteristics in multiple ways. These include changes in the following membrane properties: _____ , _____ , ______ , ______.

A

Cholesterol
fluidity, thickness, compressibility, permeability, curvature.

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

_______ lipids are extremely important due to their functions in cell signaling pathways and imparting organelle membrane identities.

A

Phosphatidylinositol lipids

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

______ of the 3, 4, and 5 position of the inositol sugar play a central role in its function.

A

Phosphorylation

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

_____ is a unique phospholipid whose fatty acid chains present almost exclusively in _____. It facilitates the chemiosmotic events associated with oxidative phosphorylation.

A

Cardiolipin
Mitochondria

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

The _______ synthesizes most phospholipids. They are then modified in the _____.

A

Endoplasmic reticulum
Golgi apparatus

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

The enzymes that produce phospholipids are located on the _____ surface of the ER membrane.

A

Cytoplasmic

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

Phospholipids start in the ____ leaflet of the ER membrane and then random transfer between leaflets occur using enzymes until equilibrium is reached.

A

Cytosolic

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

Asymmetry of phospholipids in the membrane (higher concentration of different types on the leaflets depending on function) is due to ____ _____.

A

Selective translocation

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

______ randomly flip phospholipids between the leaflets

A

Scramblases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

____ and ____ selectively transfer the phospholipids between leaflets.

A

Flippases and floppases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Initial equilibrium between leaflets in the ER is symmetric and is produced via _____.

A

Scramblases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

_____ flip lipids in both directions randomly.

A

Scramblases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Phosphatidylserine is ____ distributed among the leaflets in the ER.
By the time it reaches the plasma membrane, almost all the Phosphatidylserine is located on the ____ leaflet. Specific triggers flip the PS to the _____ leaflet. For example when coagulation or phagocytic functions are triggered.

A

Equally
Cytosolic
Noncytosolic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

The enzymes that glycosylate membrane lipids and proteins in the ER are located in the ____ of the organelle. Therefore, the sugars of glycolipids and glycoproteins are present on the _____ of the membrane. Functions of glycolipids include acting as receptors and assisting in cell to cell recognition.

A

Lumen
Surface

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Glycolipids are synthesized _____ , meaning they are only present on the noncytosolic leaflet of the ER. They are then randomly distributed by scramblases

A

Asymmetrically

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Different organelles have different concentrations of ____ and ____.

A

Lipids and proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

_____ create a thicker bilayer that can trap specific proteins with longer transmembrane domains, known as a ____.

A

Sphingolipids
Lipid rafts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Another type of special membrane domain is a _____ , creating a curved membrane that plays roles in signal transduction, regulation of metabolism, cancer, and a site of endocytotic vesicle formation.

A

Caveolae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

______ membrane proteins are anchored in the lipid bilayer either by having part of their polypeptide chain embedded or traverse one or both membrane leaflets or being covalently bound to a lipid that is embedded in the lipid bilayer.

A

Integral

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

_____ membrane proteins associate with integral membrane proteins or membrane lipids and are easier to displace.

A

Peripheral

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Using the picture, which proteins are integral and peripheral?

A

Proteins 1 through 6 are integral (trans membrane)
proteins, seven and eight are peripheral

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Membrane proteins are synthesized in the _____ and modified in the ____ , similar to lipids.

A

ER
Golgi

44
Q

A remarkably large portion of membrane proteins are _____, which occurs in the ER and chains are modified in the Golgi.

A

Glycosylated

45
Q

Functions of glycoproteins include:

A

Modulation of membrane surface properties, cell adhesion, and cell identification

46
Q

This photo represents

A

Glycosylation of a membrane protein

47
Q

Like glycolipids, the sugars covalently attached to membrane proteins, are also restricted to the _____ leaflet.

A

Non-Cytosolic

48
Q

Define glycocalyx

A

Extensive oligosaccharide additions on the plasma membrane that provide protection. these structures can be found in the intestinal epithelial cells.

49
Q

Practice question

A

B

50
Q

Practice question

A

B

51
Q

Practice question

A

E , leaflet asymmetry increases during flow from the ER to the Golgi to the plasma membrane

52
Q

The nucleus is surrounded by a double membrane system called the ____, which disassembles during mitosis. Regulated RNAs and proteins in and out of the nucleus occurs at _____.

A

Nuclear envelope
Nuclear pores

53
Q

In many cells, sites of ribosomal RNA transcription and ribosome assembly are called _____, they can be observed through differential staining properties.

A

Nucleoli

54
Q

The nucleus is physically supported by the ______, a fibrous structure, hypothesized to help organize nuclear functions and by the _____, a meshwork of filaments that underlays the nuclear envelope.

A

Nuclear matrix
Nuclear lamina

55
Q

More compact, less transcriptionally active regions of the nucleus are referred to as _____. Less compact more active regions are called _____.

A

Heterochromatin
Euchromatin

56
Q

Each nuclear pore is composed of about 30 different pore proteins called _____. Pores are semi permeable for molecules up to about 60,000 daltons where it becomes nonpermeable and must be actively transported.

A

Nucleoporins

57
Q

_____ are the major sites of energy production in the cell converting pyruvate and NADH into ATP via aerobic respiration.

A

Mitochondria

58
Q

The electron transport chain in mitochondria is located on the _____ membrane. The inner membrane is folded, forming tubules called _____.

A

Inner
Cristae

59
Q

In the mitochondria, where can mitochondrial DNA, ribosomes, and enzymes that facilitate beta oxidation acid cycle be found?

A

The inner matrix space

60
Q

In a resting state mitochondria can be _____. In a high respiratory activity state, mitochondria form a _____. This occurs via fission and fusion.

A

Fragmented
Hyperfused network

61
Q

Mitochondria generally localize where ATP is needed. Examples of this include:
1. _____
2. _____

A

Between muscle fibers
Wrapped around sperm flagella

62
Q

Mitochondria contain a single circular chromosome with ____ genes. Signaling between the nucleus and the mitochondria is called ____ and from the mitochondria to the nucleus is called_____, to ensure proper gene expression. Mitochondrial inheritance is _____.

A

40
Anterograde
Retrograde
Maternal

63
Q

Mutations that disrupt synthesis of the mitochondrial lipid cardiolipin lead to _____ and ____ disorders.

A

Cardiomyopathies
Neurodegenerative

64
Q

The _____ endoplasmic reticulum contains ribosomes. The ER synthesizes ____ and ____.

A

Rough
Lipids
Proteins

65
Q

Cells that are specialized for protein secretion tend to have a well developed _______ because they make a lot of proteins and transport then outside of the cell.

A

Rough ER

66
Q

The smooth ER functions in ____, ____, ____.

A

Lipid synthesis, detoxification, and Ca++ signaling.

67
Q

In the absence of an ER targeting signal, ribosomes remain _____ and release the newly formed proteins into the _____.

A

Free
Cytoplasm

68
Q

In the presence of an ER targeting signal sequence, ribosomes bind to the ____ and the newly formed protein will be inserted into the ____.

A

ER
ER

69
Q

The ER targeting information is contained within the ______ not the ____.

A

Protein
Ribosome

70
Q

Most proteins synthesized by the ER are glycosylated by the addition of a common _______ oligosaccharide.

A

N-linked

71
Q

Describe what is occurring in this picture

A

A sugar is preassembled on a lipid called dolichol and is then transferred to the polypeptide by oligosaccharyl transferases. The transferase active sites are located in the ER lumen, thus the sugar groups are always located on the non cytosolic side of membranes

72
Q

Protein folding in the ER is carefully monitored and regulated via _____ proteins. Misfolded proteins are dangerous and can cause diseases.

A

Chaperone

73
Q

What is the ER-Associated protein Degradation (ERAD) pathway?

A

Proteins that cannot be correctly folded are translocated into the cytoplasm, and then de-glycosylated, ubiquitinated, and targeted by proteasomes for destruction

74
Q

ATF6, IRE1, and PERK are 3 different pathways that monitor protein _____ problems in the ____.

A

Folding
ER

75
Q

When BiP (chaperone protein) is bound to ATF6, the degradation pathway is ______. Misfolded proteins pull BiP away and _____ the degradation pathway.

A

Inactive
Activates

76
Q

If protein misfolding isn’t corrected the ____ ____ ____ activates the signaling pathways that prime cells for ____.

A

Unfolded Protein Response (UPR)
Apoptosis

77
Q

The _____ ER is associated with steroid synthesis and metabolism.

A

Smooth

78
Q

Calcium is an important signaling molecule and is stored in the ____. The calcium concentration in the cytoplasm stays very low due to ____ in the ER lumen.

A

ER
Ca2+ pumps

79
Q

Define malignant hyperthermia

A

Mutations of calcium pumps lead to energy expenditure due to pumping calcium out of the cytoplasm which raises body temperature to potentially fatal levels

80
Q

Most detoxification occurs in the ____ ER, carried out by ____ family of enzymes. Important in liver cells.

A

Smooth
cytochrome p450

81
Q

The ___ face of the Golgi apparatus receives vesicles from the ER. The ____ face of the Golgi packages products after modification. Most common modification is _____.

A

Cis
Trans
Glycosylation

82
Q

N linked Glycosylation occurs in the ____. The ____ modifies N linked glycoproteins received from the ER.

A

ER
Golgi

83
Q

As proteins move from the sis, medial, trans cisternae of the Golgi they encounter a highly ordered set of processing enzymes that catalyze specific reactions, adding and removing specific ____ groups to Nlinked and Olinked oligosaccharides.

A

Sugar

84
Q

Genetic defects in Golgi enzymes results in _________, a group of over 100 monogenic human diseases with deficits in the synthesis of oligosaccharides

A

Congenital Disorders of Glycosylation (CDG)

85
Q

The ______ is a cellular sorting station.

A

Golgi

86
Q

If a protein is sent to a _____, the protein will be digested. Degradative enzymes that requires a pH of 5 is called ____ _____, enzymes will not function in the cytoplasm. ______ maintains the acidity of a lysosome by pumping H+ into the lysosome.

A

Lysosome
Acid hydrolases
Vacuolar H+ ATPas (vATPase)

87
Q

In long-lived cells, lysosomes can accumulate non degradable material giving rise to a yellowish pigment called _____.

A

Lipofuscin

88
Q

______ refers to the uptake of extracellular material via invagination of the plasma membrane.

A

Endocytosis

89
Q

______ refers to the nonselective uptake of soluble molecules and fluid

A

Pinocytosis

90
Q

______ involves the engulfment of large particles, dead cells and debris

A

Phagocytosis

91
Q

______ _____ ______ allows selective uptake of specific molecules

A

Receptor mediated endocytosis

92
Q

Lysosomes can also digest a cells own macromolecules and organelles through the process of ____.

A

Autophagy

93
Q

The best understood form of autophagy involves formation of a double membrane vesicle called a _____, which engulfs, cytoplasmic material, and then fuses with the lysosome.

A

Autophagosome

94
Q

_____ _____ _____ are caused by genetic defects that affect one or more lysosomal hydrolases. Most often affect the nervous system. In ____ ____ ____ the enzyme missing in an LSD is injected or infused, and makes its way to the lysosome via endocytosis.

A

Lysosomal storage diseases (LSD’s)
Enzyme replacement therapy

95
Q

All pathways to the lysosome pass first through the ____, and organelle that sorts cargo to different destinations in the cell. This includes endocytic and phagocytic vesicles.

A

Endosome

96
Q

As the endosome matures, the pH _____, and the endosome forms ______ that are delivered to the lysosome.

A

Decreases
Multivesicular bodies

97
Q

______ is an organelle that is involved in detoxification reactions, including the production and removal of hydrogen peroxide. It also breaks down long fatty acid chains.

A

Peroxisomes

98
Q

The _____ is the term for the main non-organelle compartment of the cell. It contains soluble ions and enzymes.

A

Cytosol

99
Q

The ____ is responsible for translation of mRNA into a protein

A

Ribosome

100
Q

______ a sight of protein degradation specific for proteins that are tagged with poly-ubiquitin chains. Found in the cytosol.

A

Proteasomes

101
Q

Major classes of cytoskeleton proteins include ____ , ____, _____ and are found in the ____.

A

Actin, microtubules and intermediate filaments

cytosol

102
Q

Practice question

A

A, exchange lipids and proteins

103
Q

Practice question

A

C

104
Q

Practice question

A

E, ribosomes are assembled in the nuclei

105
Q

Practice question

A

See picture

Fundamentals Of Medicine: Exam 1 (18 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions