1.2 cells Flashcards
(111 cards)
1
Q
what is a cell?
A
-basic unit of life
-small membrane bound structure containing several small structures called organelles.
2
Q
what’s a eukaryotic cell?
A
any cell that has a nucleus
many membranous structures inside their cells. (organelles)
3
Q
what cells don’t have a nucleus?
A
red blood cells/ phloem sieve tube cells
4
Q
what is a nucleus?
A
largest organelle found inside animal cells and the second largest found in plant cells (after the vacuole)
5
Q
function of nucleus
A
-contains DNA
-controls the activities of the cell
6
Q
what are the 2 membranes that bound nucleus
A
nuclear envelope
nucleoplasms
7
Q
nuclear envelope…..
why do they have pores/
outer membrance
A
- with pores to allow transport of mRNA and nucleotide
- outer membrane is continuous with E.R
8
Q
function of the nuclear envelope
A
separates the contents of the nucleus from the cytoplasm
9
Q
what does the nucleoplasm contain?
A
contains chromatin
10
Q
what is chromatin
A
coils of DNA, bound to protein
11
Q
function of chromatin
A
condenses into chromosomes during cell division
12
Q
what does nucleolus do?
A
produces rRNA, tRNA and ribosomes
always stains darker
13
Q
where is mitochondria found?
A
found in both animal and plant cell
14
Q
function of mitochondria
A
site of ATP production during aerobic respiration
15
Q
how is the golgi body formed?
A
formed from rough ER being pinched off at the end to form small vesicles. some join together to form the Golgi body
16
Q
what do the vesicles that are pinched off the other end of the golgi body do
A
these secrete their contents via exocytosis when they fuse with the cell membrane
17
Q
function of the golgi body?
what does it produce
A
-modifies/packages proteins to leave from the cell
-produces lysosomes (DE) and glycoproteins
-produced enzymes,
-transports and stores lipids
18
Q
when are lysosomes produced?
A
produced when portions of the Golgi body pinch off
19
Q
function of lysosomes
what do phagocytes use lysosomes for
A
-destroy worn out organelles in the cell
-digest material that has been taken into the cell
20
Q
what are these digestive enzymes used for?
A
to destroy worn out organelles and to destroy foreign material
21
Q
where are centrioles found?
what cells
A
found in animal cells and most protocists
22
Q
describe the vacuole in an animal cell
A
small, temporary vesicles and may occur in large numbers
23
Q
describe the vacuole in a plant cell
A
large and permanent fluid-filled sac bounded by a single membrane
24
Q
what does a vacuole contain?
what is it surrounded by?
A
-sell sap
- surrounded by the tonoplast membrane
25
what does cellulose cell wall consist of?
is it permeable or non permeable?
cellulose microfibrils embedded in a polysaccharide matrix.
it is permeable
26
function of cellulose cell wall?
-provides strength/support
- transport of solutes
-cell to cell communication via the plasmodesmata
27
structure of a ribosome?
(made of?
found where)
1 large/1 small sub unit
made of ribosomal RNA and protein
found free or attached to the roughER
28
function of ribosome?
protein synthesis
29
What are ribosomes in eukaryotes?
80s
30
what does nuclear pores allow?
allow the transport of mRNA and ribosomes out of the nucleus.
31
structure of the endoplasmic recticulum?
2 types, rough ER: (covered with ribosomes and linked to the nuclear membrane )
smooth ER (no ribosomes)
both flattened into sacks cisternae
32
what is cisternae?
fluid-filled spaces between the membranes
33
function of the rough endoplasmic reticulum?
- transports proteins made by the ribosomes
34
function of the smooth ER
synthesise/transports lipids
35
what is the cell theory?
states that new cells are formed from other existing cells (mitosis) and that the cell is a fundamental in all living organisms
36
explain viruses......
-extremely small
- non cell (no cytoplasm/no chromosomes/no organelles)
- exist as an inert 'viron' when outside a cell
37
how do viruses work when in the body?
take over a cell's metabolism & multiply within the host cell
38
what are viruses that attack bacteria ?
bacteriophagus
39
what does each virus particle have?
a core of nucleic acid surrounded by a protein coat called the capsid
40
what are the 3 types of muscle tissue?
-skeletal
-smooth
-cardiac
41
properties of skeletal muscle....
attached to the skeleton, capable of contracting and relaxing, voluntary control.
42
properties of cardiac muscle....
walls of the heart, appear striated (striped) and are under involuntary control
43
properties of smooth muscle ...
l organs, except the heart,
spindle-shaped,
under involuntary control
44
properties of epithelial tissue
types of epithelial tissues
- nerve endings/ no blood vessels
-simple squarmous/simple cuboidal/ simple columnar ciliated
45
explain simple squarmous....
- single layer of flattened cells with disc-shaped central nuclei and sparse cytoplasm
-basement membrane
46
function of the simple squarmous...
allows passages of materials where protection isn't important
47
location (squarmous)
line the Bowman's capsule of the kidney
48
function of simple cuboidal
secretion and absorption
49
location of simple cuboidal
found in the kidney nephron and ducts of the secretory glands
50
simple cuboidal.....
single layer of cubelike cells with large, spherical central nuclei (on a basement membrane)
51
simple colimnar.......
-single layer of tall cells with round to oval nuclei
-cells have cillia if lining a tube which substrates move through
-known as ciliated columnar epithelial cells
52
location of simple colimnar
found lining the (cilia move mucus)
and the ovaries (cilia move the egg)
53
what is adipose tissue
fatty acid
54
properties of connective tissue
consists of...
in a ...
consists of cells, elastic and collagen fibres in an extracellular matrix
55
function of connective tissues
tendons hold bone to bone
binds/supports tissues
56
what does adipose tissue equal
fatty acids
57
definition of an organ
a group of several different tissues working together to carry out a particular function for the whole organism
58
example of an organ
heart
59
definition of organ system
a group of organs working together with a particular role
60
example of organ system
digestive system
61
explain the structure of chloroplasts
double membrane
thylakoids, stroma and granum
62
what is stroma
the fluid found between the double membrane with ribosomrs/ lipids/ circular DNA and possible starch
63
what is thylakoids?
where photosynthesis takes place
often form coin-like stacks (grana) linked by lamelle
64
what is granum?
stack of thylakoids
65
why are thy thylakoids in stacks?
they mean bigger surface are for trapping light energy
66
function of chloroplast
contain photosynthesis pigments which trap light for photosynthesis
67
structure of plasmodesmata
microscopic channels whcih cross the cell walls of plant cells
68
explain the function of plasmodesmata
allows transport of materials and water
69
how do you get from mm to microns
x100
70
micros to mm
divide by 100
71
how do you work out the magnification of an image
image size/actual size
72
work out actual size
image size/magnification
73
similarities of mitochondria and chloroplasts
-double membrane
- 70s ribosomes for protein synthesis
- circular DNA
- highly folded inner membranes
- Fluid-filled
- both produce ATP
74
differences between mitochondria and chloroplasts
mitochondria- aerobic respiration, inner matrix, cristae
chloroplasts- photosynthesis, stroma, thylakoid membranes, thylakoids with chlorophyll to absorb light energy
75
what is cristae?
folds of inner membrane
76
what is a prokaryote cell
an organism that contains no membrane bound organelles
(nucleus)
77
what are the 2 types of prokaryote cells
bacteria
archaea
78
differences between prokaryote and eukaryote cells
(7 thing)
p- small cells, no membrane bound organelles, dna is free in the cytoplasms, no nucleus membranes or ER, smaller ribosomes, cell wall contains nurein
e- larger found in plant/animal/fungi/protoctists, membrane bound organelles, DNA on chromosomes, membrane bound nucleus, larger ribosomes, cell wall in plants made of cellulose
79
structure of the nucleus
dna is found here
contains the nucleolus(has ribosomes and rRNA
large round organelle surrounded by a double membrane.
(nuclear envelope)
contains nucleoplasm
80
what do nuclear pores do
allow the exchange of mayerials
81
what does mRNA contain
makes protein
82
structure of mitochondria
oval, double membrane (outer/inner)
inter membrane space
83
explain the inner membrane of the mitochondrial
highly folded into cristae which increases surface area for ATP synthesis
matrix is a viscous liquid which contains enzymes (inner membrane)
84
structure of the plasma membrane
2 layers of phospholipids embedded with proteins
85
function of the plasma membrane
regulates the movement of substances in and out of the cell
86
structure of the golgi body
flattened sacks (cisternae) with smaller vesicles around it. they punch off the end of the golgi body&can fuse with the plasma membrane
87
structure of lysosome
when does it form?
a sac containing digestive enzymes which can digest materials taken in by phagocytosis
form when small portions of the golgi body pinch off
88
why do the enzymes have to be kept away from the rest of the cell
they would destroy it
89
where are centrioles located
located outside the nucleus in the centrosome
90
function of the centrioles
makes the spindle fibres
91
structure of the cytoskeleton
fibrous network formed from/by different proteins of long chains of amino acids
92
function of cytoskeleton
major role in the movement of the cell and some cell organelles in the cytoplasm
93
where do plant cells gain their energy from
sunlight, cells in their leaves contain many chloroplasts
94
why are thylakoids green?
contain chlorophyll in the thylakoid membrane
95
structure of the cell wall
rigid layer that surrounds the cell membrane, made of cellulose (B glucose)
96
what are the pores in the cell wall called
plasmodesmata
97
function of the cell wall
provides support by keeping it rigid
stops the cell bursting
fully permeable, enabling water and other substances to pass through it
98
what does the plasmodesmata allow
the cytoplasm of neighbouring cells to connect
99
structure of the vacuole
large sac in the cytoplasm surrounded by a single membrane
consists cell dap
100
what's the membrane around the vacuole
tonoplast
101
function of the vacuole
maintaining the cell in a turgid state which provides support to the plant
102
prokaryote structures are....
smaller less complicated
103
cell wall in prokaryote
made of peptidoglycon
not cellulose
104
plasma membrane in prokaryote
cell membrane that has an unfolding called the mesosome
not mitochondria, site of respiration in prokaryotes
105
ribosomes in prokaryotes
70s
106
DNA in prokaryote
no nucleus
DNA floats free in the cytoplasm, contain loops of DNA (plasmids)
107
Flagella in the prokaryote
aid with movement
108
function
capsule in prokaryote
stop the cell drying out or preventing phagocytosis by white blood cells
109
structure of the nucleus
large, round organelle with a double membrane
contains the nucleolus, which produces ribosomes and rRNA.
contains nucleoplasm ( DNA in the form of chromatin)
nuclear envelope contain nuclear pores
110
structure of the mitochondria
oval and have a double membrane
outer/ inter membrane space/ inner membrane (folded into cristae)
111
structure of the Golgi apparatus
a stack of flattened membrane bound sacks known as cisternae with smaller vesicles around it
