Cell and Tissue Structure 2 Flashcards

1
Q

which three organelles are involved in production of functional proteins?

A

ribosomes, SER and RER, golgi apparatus

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

where are ribosomes found?

A
  • free floating in cytoplasm
  • bound to the surface of the RER or nuclear envelope
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

describe structure of ribosomes

A
  • made of 2 subunits
  • composed of proteins and rRNA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is function of ribosomes?

A

synthesis of polypeptide chain by attaching a.a. in sequence as directed by DNA

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

what does ER do?

describe structure of ER?

A

function:

ER very important in folding chain of a.a. into correct functional protein

structure:

  • composed of membrane that is continous with the nuclear envelope
  • forms folds of membranes called cisternae
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q
  • describe what happens to polypeptide chains in the RER (2)
  • which proteins are processed by RER?
A

(translation happens in ribosomes) immediately goes into RER:

  • most proteins are tagged e.g glycosylation (addition of carb)
  • folded into their specific 3D structure
  • almost all cellular and secretory proteins are processed by RER
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what are the general functions of SER?

but…?

A

generally important for synthesis of carbs and lipids -> can breakdown lipids and synthesis new fatty acids

BUT: have specific functions in different cell types

  • e.g. SER in muscle cells regulates calcium ion storage.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is role of golgi apparatus?

A

modify and package proteins for transport to different areas of the cells / vesicles to leave the cell

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

what are two ends of GA called?

A

GA has the:

  • cis surface: PROTEINS IN HERE
  • trans surface: PROTEINS LEAVE AFTER THE STACKS
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

general summary of protein pathway

A

nucleus: DNA -> RNA

Ribosome: RNA -> Protein

RER: Protein modification

GA: protein packed and futher modified

the secreted

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

what are secretory pathways aka?

A

exocytosis

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

what are the three general secretory pathways?

A
  1. Constitutive secretion: unregulated secretion e.g. secretion of extracellular matrix proteins

2. Regulated secretion / signal mediated : requires a signal for secretion to occur. e.g. hormones

3. Lysosomal secretion: lysosomes need to be activated

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

where are lysosmes produced?

A

Golgi Apparatus

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

define lysosomes

A

membrane bound vesicles containing digestive enzymes

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

what can enzymes in the lysosomes do?

A
  1. break down food or other organelles (autophagy)
  2. breakdown invading organisms (bacteria)
  3. breakdown cell itself (autolysis)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what do defects in lysosomes cause?

how many diseases?

A

lysosomal-storage diseases

50 childhood diseases

17
Q

what is endocytosis? what does it require?

A

process by which substances / organisms can entre cells surrounded by a membrane formed from internal budding of cell membrane. requires energy

18
Q

what are the three types of endocytosis?

A
  1. phagocytosis (cell eating)
  2. pinocytosis (cell drinkin)
  3. receptor mediated or clathrin mediated endocytosis. clathrin are proteins found under cell membrane. can signal cell membrane to pinch off at that point
19
Q

what are peroxisomes?

where originate?

what do they specifically contain?

A

def: membrane bound vesicles containing a number of catalytic enzymes responsible mainly for break down of fatty acids

originate: from RER

contain: catalase -> break downs hydrogen peroxide (common product of enzyme peroxisome)

20
Q

what is a perixosomal disorder?

A

diseases where get accumulation of hydrogen peroxide due to absence of peroxisomes

e.g. Zellweger syndrome

21
Q

does mitochondria have its own DNA?

A

yes - codes for most of proteins in mitochondria

22
Q
A
23
Q

apart from ATP production, what else mitochondria used for?

A

initiating apoptosis

24
Q

what do mitochondria disorders commonly effect?

  • how many?
  • can be caused by mutations in what?
A
  • muscle and nervous systems (high energy requirements)
  • over 40 diseases
  • mutations in mtDNA or nuclear DNA