Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Biology 2 > 2.1.1 Cells > Flashcards

2.1.1 Cells Flashcards

1
Q

Structure and function of nucleus

A
  • nucleolus - densest part of the cell (site of ribosome production)
    contains chromatin which makes up chromosomes ( wound around histones )
    surrounded by nuclear envelope (double membrane) which has nuclear pores to let mRNA and ribosomes through
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Structure of mitochondria

A

surrounded by double membrane
inner membrane folds to form cristae
cristae forms matrix which contains enzymes needed for aerobic respiration
small mitochondrial DNA and ribosomes found in matrix

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

Structure of chloroplasts

A

surrounded by double membrane
thylakoids (membrane bound compartments containing chlorophyll) stack to form grana
grana are joined by lamellae (thin and flat thylakoid membrane)

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

Structure of ribosomes

A

found either freely in the cytoplasm or on the rough ER
80s in eukaryotic
70s in prokaryotic, mitochondria and chloroplasts

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

Function of ribosomes

A

site of translation

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

Structure of rough endoplasmic reticulum

A

formed from folds of membrane continuous with the nuclear envelope
surface covered in ribosomes

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

Function of rough endoplasmic reticulum

A

processes proteins made by the ribosomes by folding primary structures into secondary and tertiary structures

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

Function of smooth endoplasmic reticulum

A

synthesises, processes and stores lipids carbohydrates and steroids

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

Structure of golgi apparatus

A

flattened sacs of fluid-filled membrane
has secretory vesicles to transport molecules
vesicles enter the cis face and leave via the trans face

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

Function of golgi apparatus

A

modifies proteins and lipids
packages them into golgi vesicles
vesicles transport proteins out of the cell (exocytosis), or to membrane bound organelles

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

Structure and function of vesicle

A

membrane-bound sac
used for transport and storage

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

Structure and function of lysosome

A

specialist vesicle which contains hydrolytic enzymes (break biological molecules down)
used by immune system in phagocytosis

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

Structure of centriole

A

hollow fibres made of microtubules
two centrioles at right angles to each other form a centrosome

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

Function of centrioles

A

form centrosomes which organise spindle fibres in cell division

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

Structure of microtubules

A

made of alpha and beta tubulin combined to form protofilaments
- 13 protofilaments in a cylinder make a microtubule

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

What is a cytoskeleton made of

A
  • microfilaments
  • microtubules
  • intermediate fibres
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Structure and function of microfilaments

A

made of actin
responsible for cell movement and contraction during cytokinesis

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

Function of microtubules

A

acts as tracks for the movement of organelles around the cell
make up spindle fibres used for cell division

19
Q

Function of intermediate fibres

A

provide mechanical strength and help maintain integrity

20
Q

What is the cell wall made of

A

peptidoglycan in prokaryotes
cellulose in plants

21
Q

Organelles that are always present in prokaryotes

A
  • cell wall
  • cell membrane
  • cytoplasm
  • circular strand of DNA
  • 70s ribosomes
22
Q

Organelles that are sometimes present in prokayotes

A
  • flagellum
  • slime capsule
  • infolding of surface membrane
  • plasmids
  • pili
23
Q

Structure and function of flagellum

A

hair like structure with basal hook that attaches to cell membrane
rotates - mechanical motor

24
Q

Function of slime capsule

A

protects bacteria from drying out
protects from attack from immune system cells

25
Function of plasmids
small loops of DNA that can be passed between bacterial cells often contain genes for antibiotic resistance
26
Describe the role of the nucleus in protein production
- ribosomes are produced in the nucleolus - DNA is transcribed into mRNA which leaves the nucleus via the nuclear pore to a ribosome on the rough ER
27
Describe the role of the rough ER in protein production
polypeptides move into the rough ER cisternae primary structures are folded into secondary and tertiary structures proteins are packaged into vesicles
28
Describe the role of the golgi in production of proteins
vesicle fuses with cis face golgi and releases protein into golgi protein is modified and packaged into secretory vesicle vesicle leaves the trans face golgi and fuses to the cell membrane to release the protein through exocytosis
29
What is the membrane surrounding the vacuole called
tonoplast
30
What is resolution
the smallest distance that two points can be distinguished from each other
31
Benefits of light microscopes
- cheap - easy to use - can view living organisms and cells
32
Drawbacks of light microscopes
- maximum resolution - 0.2 micrometres - maximum useful magnification - x1500 - therefore cannot be used to observe smaller organelles (rough ER etc) - 2D images only
33
How does a transmission electron microscope work
an electron beam is transmitted through the specimen denser parts of the specimen absorb more electrons so appear darker - specimen are dead and dipped in heavy metals (lead) to scatter electrons then embedded in wax
34
Benefits of using a transmission electron microscope
- higher resolution - 0.5 nm - higher magnification - over x500,000
35
Drawbacks of using a transmission electron microscope
- black and white 2D images - dead specimen due to vaccum - lengthy treatment to produce very thin specimen
36
How do scanning electron microscopes work
a beam of electrons hits the specimen and is scattered electrons are detected, forming an image - SEM's can produce 3D images of the surfaces of specimens
37
Benefits of scanning electron microscopes
- images of external, 3D structure can be observed - maximum resolution of 3-10nm - maximum magnification of x 500,000
38
Drawbacks of scanning electron microscopes
- maximum resolution lower than TEM - black and white images - can colour digitally - dead specimen due to vaccum
39
Benefits of staining specimen
increases the contrast - so different organelles can be visible e.g. nuclei - so different biological molecules are visible e.g. starch grains
40
What is the use of methylene blue
stains DNA blue
41
What is the use of acetic orcein
stains DNA red
42
What is the use of iodine
stains starch blue/black stains cell walls brown/yellow
43
What are the different types of sample preparation
- dry mount - wet mount (specimen in liquid such as water or an immersion oil) - squash slides - smear slides
44
Describe how to measure the size of X using a light microscope
use eyepiece graticule calibrate the graticule using a stage micrometre measure the length of X in eyepiece units use calibrated epu to calculate the actual length of X

Biology 2 (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions