ANAT241 L1 Flashcards
(74 cards)
1
Q
What are 3 characteristics of the basic structure of a human cell?
A
- Bound by plasma membrane
- Contains cytoplasm
- Contains organelles
2
Q
What are 2 components of cytoplasm, of a human cell?
A
- viscous fluid
- filaments and fibres forming cytoskeleton
3
Q
What is viscous fluid otherwise known as?
A
cytosol
4
Q
What are 2 components of organelles, of a human cell?
A
- membrane and non-membrane bound
- includes nucleus (control centre, houses DNA)
5
Q
What are 2 components of the nucleus?
A
- control centre
houses DNA
6
Q
What are cells surrounded by?
A
The plasma membrane
7
Q
What is the purpose of the plasma membrane?
A
Separate the inside of the cell from the outside environment
8
Q
What is a plasma membrane?
A
A semi-permeable, selective barrier
9
Q
The plasma membrane surrounds the cells. What does it also surround?
A
Membrane-bound organelles
10
Q
What is a plasma membrane?
A
Dynamic
11
Q
What are the 3 key components of the plasma membrane?
A
- phospholipids
- cholesterol
- proteins
12
Q
What are the 3 key functions of the plasma membrane?
A
- Protection
- Transport
- Communication
13
Q
What are proteins essential for?
A
Cell function
14
Q
What are the 2 groups of membrane proteins?
A
Integral and peripheral
15
Q
What are some characteristics of integral membrane proteins?
A
- Anchored to membrane
- Some part way
- Some span entire membrane
16
Q
What is the name for integral membrane proteins that span the entire membrane?
A
Transmembrane proteins
17
Q
What are some characteristics of peripheral membrane proteins?
A
- on the outside or inside of membranes
- may be attached to integral proteins, or phospholipids
18
Q
What do cells need in order to know what to do?
A
Signals
19
Q
Where do most signals come from?
A
Outside the cell
20
Q
What are the 3 ways a signal can get to a cell?
A
- diffuse across plasma membrane
- enter through channels or carriers
- they don’t
21
Q
How does a signal reach a cell, through: diffusing across the plasma membrane?
A
small lipophilic molecules (e.g. gases, vitamins, steroid hormones)
22
Q
How does a signal reach a cell, through: entering through channels or carriers?
A
small molecules (e.g. Ca2?, thyroid hormone)
23
Q
What happens to a signal for it to NOT reach the cell?
A
- receptors bind a ligand outside the cell
- signal transducer inside the cell
- causes a cellular reaction
24
Q
What are the 2 key function of the skeleton?
A
help maintain cell shape and structure
25
What is the cytoskeleton essential for?
- cell division
- cell movement
- vesicle movement within cells
26
What is a cytoskeleton?
dynamic - it changes to meet the needs of the cell
27
What are the 2 key functions of a microtubule?
- resist compression
- help maintain cell shape
28
What are microtubules important for and how?
- motility
- form flagella and cilia, organelle motility
29
What are the 2 key functions of microfilaments?
- resist tension
- form cortical network beneath plasma membrane
30
What are microfilaments important for and how?
- movement
- actin and myosin interactions for muscle contraction
31
What are the 2 key functions of intermediate filaments?
- form more permanent structures
- anchor organelles
32
What are intermediate filaments important for and some examples of it?
- cell adhesion
- cytokeratin, neruofilaments, lamina
33
What are organelles?
sub cellular structures with specific functions
34
What are 2 key functions of organelles?
- often membrane-bound
- create defined areas and environments within the cell
35
What are 3 examples of 3 key organelles?
- nucleus
- endomembrane system (endoplasmic reticulum, Golgi, vesicles)
- mitochondria
36
What is the mitochondria?
the site of cellular respiration
37
What are 2 key characteristics of the mitochondria?
- double membrane structure
- number per cell depends on energy demands
38
What is the key function of the mitochondria?
generate energy
39
How does the mitochondria generate energy?
- consume glucose and oxygen
- produce CO2, water and energy: ATP
40
What is the nucleus?
the control centre of the cell
41
How many nuclei are normally found per cell?
one
42
What are features that the nucleus contains?
- contains most of the cells DNA (eurochromatin & heterochromatin)
- contains nucleolus (makes rRNA & ribosomal subunits)
43
What are 2 structural features of the nucleus?
- surrounded by nuclear envelope (double membrane, continuous with ER)
- inner surface lined with nuclear lamina
44
What is a nuclear envelope?
45
What is the nuclear envelope spanned by?
nuclear pores
46
What is the process of a nuclear envelope being spanned by nuclear pores?
- channel made of nucleoporins
- allows mRNA, tRNA and ribosomal subunits to move to cyotoplasm
-
47
What does the nuclear envelope being spanned by nuclear pores allow?
- allows mRNA, tRNA and ribosomal subunits to move to cyotoplasm
- allows building materials, energy and control signals into nucleus
48
What is the endomembrane system?
an interconnected system
49
The endomembrane system is an interconnected system that includes what?
- endoplasmic reticulum (ER)
- golgi apparatus
- vesicles
50
What is the function of the membrane system?
modify, package and move protein & lipids
51
What are the 2 types of endoplasmic reticulum?
- smooth ER
- rough ER
52
What is a characteristic of the smooth ER?
- lacks ribosomes on surface
53
What are 4 of the key functions of a smooth ER?
- synthesise lipids
- metabolise carbohydrates
- detoxification processes
- store calcium ions
54
Of the smooth ER, what are the store calcium ions used as?
a signal within the cell
55
What is a characteristic of the rough ER?
covered with ribosomes on outer surface
56
What is the key function of the rough ER?
its role in protein synthesis
57
What is the rough ER's role in protein synthesis?
- proteins enter lumen of rER
- proteins are modified, folded and packaged into vesicles
- transported to Golgi
58
What is the Golgi apparatus/complex?
a series of membrane sacs and vesicles
59
What is the role of the Golgi apparatus/complex?
- vesicles from ER arrive at cis face
- proteins modified, glycosylated, sorted into vesicles
- vesicles leave from trans face
60
What are 2 features of a vesicle?
- membrane bound
- move via motor proteins 'waling' along microtubules
61
What are the 2 types of vesicles?
- transport vesicles
- secretory vesicles
62
What is the role of transport vesicles?
move contents WITHIN cell
63
What is the role of secretory vesicles?
move contents OUT of cell
64
What is the process where secretory move contents out of the cell called?
exocytosis
65
Secretory vesicles are how most contents are moved out of the cell. What molecules are released during this process?
how most signalling molecules are released
66
Why do cells need to communicate?
- send and receive instructions
- coordinate functions
67
What would happen if there were no cell-to-cell communication (cell signalling)?
there would be no functionality of cells, tissues and organs
68
Cell signalling is a multi-step process, what does this process involve?
-sending, and reception, of signal
- then changes inside the cell which impacts the amount or activity of specific proteins
69
In a general sense, what is cell signalling and what does it do?
- a complex system of communications
- controls all cellular function
69
Cell signalling impacts the amount/activity of a specific proteins, how so?
- alter gene expression for a specific protein
- alter activity of a specific protein
70
What are the 3 key functions of cell signalling?
- receive signal
- transduce signal
- respond to signal
71
What is the multi-step process of cell signalling?
1. synthesis of signal molecule
2. release of signal molecule
3. transport of signal molecule to target
4. detection of signals by target cell (reception)
5. response by large cell
6. feedback
72
What must be considered, during the multi-step process, of cell signalling?
- sending the message (what the signal molecule is, how it will reach the target cell and how it will deliver the message to the right place)
- what happens after the signal is received (what pathways are activated inside the cell and what the outcome is)
- what happens when things go wrong
73
