cells Flashcards
1
Q
what is the function of a nucleus
A
contains the DNA ehich codes for protein synthesis
2
Q
what is the function of the nucelar envelope
A
seperates the DNA from the cytoplasm
3
Q
what is the function of the nucelar pore
A
allows the transport of mRNA (out of nucelus)
4
Q
what is the function of the nucelolus
A
synthesis of rRNA and robosomes
5
Q
what is the structure of ribosomes
A
- consists of 2 subunits made from ribosomal RNA (rRNA) and protein - large and small subunit
- can be free or attached to rough endoplasmic reticulum (RER)
6
Q
what is the function of ribosomes
A
protein synthesis
7
Q
what is the structure of the rough endoplasmic reticulum
A
- forms a system of flattened sacs (cisternae) which are continuos with the nuclear membrane and may link to the Glori appartus
- RER has ribosomes attached
8
Q
what is the function of the rough endoplasmic reticulum
A
transports proteins which are synthesised by the ribosomes attached
9
Q
what is the structure of the smooth endoplasmic reticulum
A
- forms a system of flattened sacs (cisternae) which are continuous with the nuclear membrane and may link to the golgi apparatus
- has no ribosomes attaches
10
Q
what is the function of the smooth endoplasmic reticulum
A
the synthesis and transport of lipids
11
Q
what is the structure of the Golgi body/ apparatus
A
- is a similar structure to ER however is more compact
- surrounded by vesticies
12
Q
what is the function of the Golgi body/ apparatus
A
- chemically modifies proteins
- produces lysosomes
- produces glycoproteins
- packages proteins for secretion out of the cell
13
Q
what is the strcuture of the mitochondria
A
- rod shaped and 1-10 micrometres diametre
- has a double membrane, the inner and outer membrane
- the membranes are separated by a narrow fluid filled inner membrane space
- the inner membrane is folded to form structures called cristae
14
Q
what is the function of the mitochondria
A
- the site of aerboc respiration which synthesises ATP
- the cristae increases the suface area on which part of the respiratory process takes place
15
Q
what is the structure of vacuoles/vesticles (animal)
A
- small membrane bound organelle
16
Q
what is the function of vacuoles/vesticles (animal)
A
- act as a contractile vacuole to maintain osmotic pressure
17
Q
what is the structure of vacuoles/vesticles (plant)
A
- large membrane bound organelle surrounded by a tonoplast
18
Q
what is the function of the vacuoles/vesticles (plant)
A
- storage of ions and organic molecules (eg proteins and maintaining osmotic pressure)
19
Q
what is the structure of centrioles
A
- consists of two hollow cylinders postitioned at right angles to one another
20
Q
what is the function of centrioles
A
are used in spindle fromation (microtubes) in cell division
21
Q
what is the structure of lysosomes
A
- 1.0 um in diametre
- small vacuoles fromed when small prtions of the golgi body are pinched off
22
Q
what are the function of lysosomes
A
- they contain and isolate digestive enzymes
- they can release these enzymes and destroy organelles
- digestion of materials which has been taken into the cell
- eg white blood cells engulf bacteria by phagocytosis and the lysosomes are used in the digestion of the bacterium
23
Q
what is the structure of the chloroplast
A
- 2-10 um in diametre, 1um thick
- have a double memebrane
- the interior is made up of a fluid called stroma, ribosomes, lipids, circular DNA and starch granuales
- there are thylakoids (flattened sacs) these form stacks which are called granum. each granum has 2-100 thylakoids between the grana the thylakoids from iamellae
24
Q
what is the function of the chloroplast
A
- site of photosynthesis
- the thylakoids contain photosynthetic pigments such as chlorophyll
25
what is the structure of cellulose cell wall
- made of cellulose microfibrils in a polysaccharide matrix
26
what is the function of cellulose cell wall
- prevent osmotic lysis (cell bursting)
- to provide strength and support
- freely permeable to water
27
what is the structure of the plasmodesmata
- a narrow thread of cytoplasm that passes through the cell wall of adjacent plant cells
28
what is the function of the plasmodesmata
- exchange of large organic materials via cytoplasmic streaming
29
what does the production of protein by a cell mean
relationships between organelles working together to produce protein within a cell
30
what is a tissue
is a group of similar cells working together to perform a function
31
what is an organ
Different types of tissues working together to perform a particular function
32
whats the organism order
simple molecule
complex molecule
cell
tissue
organ
system
organism
33
whats the difference between prokaryote and eukaryote cells
prokaryote doesnt have a nucleus and membrane bound organelles
34
what is endosymbiosis
when an organism lives within the body or cells of another organism, usually mutualistic relationship
35
what is the endosymbiotic theory
that some of the organelles in eukaryotic cells were once prokaryote cells
36
what is the evidence of the endosymbiotic theory
the facts that mitochondria, chloroplasts and prokaryotic cells:
are all the same size
divide into two by binary fission
have their own DNA which is circular
have their own ribosomes which are 70s
37
whats the process of turning a ancestral prokaryotie to an ancestral eukaryote
ancestral prokrayote-> infolding of plasma membrabne -> endosymbiosis-> ancestral eukaryote
37
why are viruses not considered to be living organisms/cells
dont have a cytoplasm
needs host to reproduce
cant grow
has no ribosomes
38
what are the characteristics of life
- movement
- respiration
- sensitivity
- growth
- reproduction
- excretion
- nutrition
39
what is included in the simple virus structure
DNA or RNA surrounded by a protein coat
40
what are the stages of protein production
1. the nucleus manufactures mRNA which is needed by ribosomes to make proteins
2. the ribosomes in the RER make proteins
3. the RER processes the proteins which are then sent in vesicles to the golgi body
4. the golgi body further processes the proteins and sends them in vesicles to the plasma membrane
5. the vesicles fuse with the plasma membrane to secrete the finished protein product
41
what organelles are in a bacteria cell
plasmids
nucleoid/naked DNA
pili
mesosome
flagellum
cell wall
cytoplasm
slime capsule
42
what is a plasmid
small loops of DNA
used in cell sharing and antibacterial resistance
43
what is a pili
help attach to other bacterial surfaces
44
what is a mesosome
site of aerobic respiration and large SA so more ATP
45
what is a slime capsule
slimy layer that protects the cell
46
types of human tissues
connective
muscle
epithelial
47
whats the function of connective tissue
supports, connects, seperates different types of organs and tissues
48
whats the structure of connective tissue
cells are contained within an extracellular matrix/fluid and may be surrounded by elastic or collagenous fibres
49
what are the types of muscle tissue
skeletal
smooth
cardiac
50
what is the structure and function of skeletal muscle tissue
used in locomotion in mamals
bands of long cells/fibres giving powerful contractions
51
what is the structure and function of smooth muscle tissue
individual spindle-shaped cell within contract rhythmically but not as powerful
found in blood vessels wals, digestive/respiartory tracts
52
whats the structure and function of cardiac tissue
cells have stripes but lack long fibres
contract rhythmically with some force but dont tire
53
what are the features of epithelial tissues
covers and lines the body
all sit on a basment membrane
54
what are the types of epithelial tissue
cupoidal
columnar
squamous
55
what is the structure and location of cupoidal tissue
cube shaped and 1 cell thick
lines kidney tubues and ducts of glands
56
what is the structure and location of columar tissue
cells are more rectangular, may have cilia present
eg lining trachea
57
what is the structure and location of sqamous tissue
consists of flattened cells
found in alveoli and lining arteries
