Brainscape's Knowledge GenomeTM

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


See full index

week 1 > introduction to cell and organelles > Flashcards

introduction to cell and organelles Flashcards

1
Q

What is a cell ?

A

The basic unit from which living organisms are made consisting of an aqueous solution of organic molecules enclosed by a membrane

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

What is the difference between eukaryotic cels and prokaryotic cells ?

A

Eukaryotic cells are organised and compartmentalised with membrane bound organelles

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

What can be found in a basic human cell

A

Nucleus
Endoplasmic reticulum
Golgi apparatus
Mitochondria
Plasma membrane
Peroxisomes and lysosomes
Cytoskeleton

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

What are organelles

A

Sub cellular compartments
Localise cell function
Usually membrane bound -> ribosomes exception
Specialised for unique functions

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

What is the nucleas ?

A

The largest organelle in the cell an contains genetic material of cell (dna) in form of chromosomes

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

What are chromosomes

A

Chromatin associated with histones
Each chromosome -> contains number of genes joined end to end with each gene coding for structure of single protein

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

The genetic blue print for all proteins (structural and enzymes) is contained where ?

A

The nucleas

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

What are the key features of the nucleas and label them

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

What is the function of nuclear membrane (nuclear envelope)

A

Double membrane layer that acts as a barrier that separates contents of nucleus from the cytoplasm

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

What is the structure of nuclear membrane

A

Inner and outer membrane
Phospholipid bilayers
Outer membrane is continuous with rough ER
Inner membrane contains nuclear lamina

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

What is the nuclear lamina

A

Structural mesh
Underneath nuclear membrane
Consists of intermediate filaments called lamins that link inner membrane proteins
Provide support

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

What is the nuclear pore and its function ?

A

Protein lined channel in the nuclear envelope.
Each nuclear pore complex consists of 30 proteins (nucleoporins)
Regulates transportation of molecules between nucleas and cytoplasm

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

What is the nucleolus ?

A

Spherical structure found in cells
Site of ribsomal rna synthesis
Production of ribosomes and ribosomal assembly

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

What are the main components of a plasma membrane ?

A

Phospholipid bilayer
Cholesterol
Carbs
Proteins
Lipid/ membrane rafts

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

What is the function of the plasma membrane ?

A

Form a barrier between each cell and its environment
Partitions cytoplasm of eukaryotes into compartment.
Ion gradients are maintained.

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

Explain the phospholipid bilayer ?

A

Thin polar membrane made up of two layers od phospholipid molecules

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

Explain phospholipid molecules

A

Amphiphilic
Consist of polar, hydrophilic head
Non polar hydrophobic tail
Form bilayer in aqueous solution
Hydrophilic heads directed outwards + hydrophobic forced together inwards

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

What do weak intermolecular forces of phospholipid allow it to do ?

A

Individual phospholipids can move freely between layers

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

What is the role of cholesterol in the bilayer

A

1:1 ratio with cholesterol
Amphiphillic
Prevent overpacking of phospholipid fatty acid tails
Stabilise an regulate fluidity of phospholipid bilayer

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

What is the importance of membrane proteins ?

A

Cell to cell adhesion
Cell-matrix adhesion and intercellular signalling

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

Membrane lipids and proteins can also conjugate with what ?

A

Polysaccharides to form glycoproteins or glycolipids

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

What does mitochondria have its own of ?

A

Genome -> always inherited from mother

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

Explain the outer membrane of the mitochondria

A

Relatively permeable
Allows free passage of small molecules

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

Explain the inner membrane

A

Thinner than outer
Has complex folds and tubules called Cristae-> provide large surface area

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

Explain the inter membrane space ?

A

Between the two membranes
Contains cytochrome c
Contains enzymes important in the etc chain

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

Explain the mitochondrial matrix

A

Site of mitochondrial DNA and ribosomes
And contain enzymes for TCA cycle

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

What are functions of mitochondria

A

ATP production and apoptosis

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

Explain apoptosis

A

Release of cytochrome c from mitochondria to cytosol
Initiates apoptosis
- occurs when cells detect significant DNA damage

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

What is the function of rough ER

A

Associated with ribosomes
Protein synthesis
Protein folding
Protein modifications

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

What is the function of smooth er

A

It is not dotted with ribosomes
Lipid synthesis
Calcium storage

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

Explain the structure of the Golgi apparatus

A

A stack of flattened membrane bound sacs called cisternae
With vesicles

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

Briefly describe function of Golgi apparatus

A

Proteins received from ER
Modified and stored for eventual destination in the cell

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

What is the function of lysosomes

A

Degrade unwanted molecules
Contain approx 50 degradative enzymes
Optimal ph 5 - therefore only work in acid environments

34
Q

What are peroxisomes ?

A

Membrane bound organelles
Present in all cells but have different functions in different cell types

35
Q

What is the function of peroxisomes

A

Perform enzymatic oxidation and contain a range of oxidative enzymes such as catalase
Break down of fatty acids in b oxidation

36
Q

What is the cytoskeleton

A

A framework of filaments and tubules

37
Q

What is the function of the cytoskeleton

A

To organise cell structure
To maintain correct shape of the cell -> organise internal structure
Supports fragile plasma membrane
Provide mechanical linkages that let tissue bear stress
Facilitate movement of organelles
Allows cell to adopt specific behaviours

38
Q

What specific behaviours does the cytoskeleton allow

A

Growth, division, motility

39
Q

What are the three types of cytoskeleton

A

Microtubles
Micro filaments
Intermediate filaments

40
Q

What are classed as the dynamic type of cytoskeleton

A

Microtubles and microfilaments

41
Q

What is classed as stable filaments ?

A

Intermediate filaments

42
Q

Explain intermediate filaments ?

A

Play a structural role
Provide mechanical strength
Consist of filaments that self assemble into larger filaments and bind to intracellular structures to each other ad to plasma membrane proteins

43
Q

What are the different intermediate filaments

A

Keratin family found in epithelial cells
Vimentin found in fibroblasts
Lamins found in nuclei of all eukaryotic cells

44
Q

Where are intermediate filaments found in terms of the skin

A
45
Q

What does the nuclear lamina provide ?

A

Nuclear organisation
Nuclear membrane support
Chromatin organisation

46
Q

Explain the structure microtubules

A

Dynamic structures
Larger than microfilaments
Made up of globular protein subunits to form polymers of either a and b tubulin

47
Q

What is the function of microtubules

A

Cell movement
Intracellular transport of organelles
Forms mitotic spindle

48
Q

Where do microtubules originate from ?

A

Specialised microtubule organising centre -> the centriole found in centrosome

49
Q

What are microtubules also associated with ?

A

Motor proteins called kinesics and dyneins

50
Q

What do kinesics and dyneins do

A

Motor proteins That attach to membranous organelles and move them about within cytoplasm
Kinesins - move cargo away from the centrosome
Dyneins - move cargo towards centrosome

51
Q

Microtubules also Orem what structure

A

Cilia and flagella

52
Q

What is the cytoskeletal compound of cilia and flagella called

A

Axonemes

53
Q

What do axonemes allow

A

Bending when microtubules slide through dynein allowing bending force

54
Q

In cilia how are microtubules arranged

A

Nine pairs of microtubules form a cylindrical structure

55
Q

What are microfilaments ?

A

Polymers of actin

56
Q

What are the functions of microfilaments

A

Skelton of actin filaments are found in specialisations such as microvilli
Membrane extensions -> lamellipodia and filopedia
Cell contraction and shape change
Cytokinesis
Form supporting network
Cell movement such as phagocytosis

57
Q

Actin associates with transmembrane and linking proteins to form what ?

A

Cell cortex - supporting mesh work

58
Q

Why do cell rarely function on their own ?

A

Because they work together cooperatively to perform a given function

59
Q

How is aggregation of cells and integration of function possible ?

A

Through cell junctions

60
Q

What are cellular junctions ?

A

Transmembrane protein complexes

61
Q

What is the function of cellular junctions ?

A

Connect plasma membrane to adjacent cells
Basement membrane, cytoskeleton and extra cellular matrix

62
Q

Briefly describe the extra cellular matrix ?

A

Molecules outside of the cell

63
Q

What are samples of cell to cell junctions

A

Adherens and desmosomes

64
Q

What is the function of adherens ?

A

Tissue integrity, motility, contractibility

65
Q

What is the cytoskeleton in an adherens junction

A

Actin

66
Q

What is the function of desmosome

A

Strong adhesion
Resist mechanical stress

67
Q

What is the cytoskeleton of desmosmes made up out of

A

Intermediate filaments

68
Q

What examples of cell-ecm junctions

A

Focal adhesions
And hemidesmosomes

69
Q

What is the function of focal adhesions

A

Cell anchorage

70
Q

What is the cytoskeleton of focal adhesions

A

Actin

71
Q

Where can desmosomes be found

A

Epidermis

72
Q

Where are focal adhesion junction used

A

Cell migration

73
Q

What is the function of hemidesmosomes

A

Cell anchorage

74
Q

What is the cytoskeleton of hemidesmosomes

A

Intermediate filaments

75
Q

Where can hemidesmosomes be found ?

A

Dermal - epidermal junction

76
Q

What is the overall function of tight junction

A

Function as gates and fences
Allow selective permeability and cell polarity

77
Q

What is the function of gate

A

Regulation of paracellular activity
Movement of substances in between cells

78
Q

What is function of the fence

A

Allow formation of apical (top side) and basolateral (bottom) intramembrane diffusion barrier

Stopped apical components mixing with components at the bottom

79
Q

Where is tight junction found

A

Epidermis - it is polarised
Has distinct top and bottom

80
Q

What is the function of GAP junction

A

Allows chemical and electrical communication
Allow passage of small molecules

81
Q

What is the structure of GAP junction

A

Cell to cell contact
Composed of hexameters of Connexins

week 1 (6 decks)

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