Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Aqa A-level Biology > Cell Structure > Flashcards

Cell Structure Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

What is the function of the Golgi apparatus?

A

To process and and package proteins into vesicles and lipids to be sent elsewhere

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

What is the function of ribosomes?

A

Where proteins are made

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

What is the function of the nucleus?

A

Contain DNA

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

What is the function of nucleolus?

A

To make ribosomes

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

What is the function of the smooth endoplasmic reticulum?

A

Synthesis and processes lipids

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

What is the function of mitochondria?

A

Produces ATP and releases energy and is the site of respiration

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

What is the function of the cell surface membrane?

A

To regulate the movement of substances in and out the cell

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

What is the function of centrioles?

A

To form the spindle for cell division

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

What is the function of the rough endoplasmic reticulum?

A

To Fold and process proteins made at ribosomes

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

What is the function of the nuclear pore?

A

Allows RNA to move between the nucleus and cytoplasm

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

What is the function of the Golgi vesicle ?

A

Stores lipids and proteins made by the Golgi apparatus and transports them out the cell

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

What is the function of a lysosome?

A

Contains digestive enzymes called lysozymes

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

What is the function of the cell wall?

A

To support cells and prevent them from changing shape

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

What is the function of the cell vacuole?

A

Helps maintain pressure inside the cell and keep the cell rigid

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

What are the similarities of eukaryotic cells vs prokaryotic cells?

A

•cell wall
•ribosomes
•cytoplasm
•cell membrane
•cell surface membranes are made from a phospholipid bilayer

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

What are the differences between eukaryotic cells vs prokaryotic cells?

A

•cell wall in prokaryotic cells are made from murein whereas cell wall in eukaryotic cells are made of cellulose
•DNA is circular in prokaryotic cells whereas it is linear in eukaryotic cells
•Ribosomes are larger in eukaryotic cells
•DNA is enclosed in nucleus in eukaryotic cells whereas it is free in the cytoplasm in prokaryotic cells
•Organelles are membrane bound in eukaryotic cells
•No capsule or pili in eukaryotic cells whereas it is present in prokaryotic cells

17
Q

What is the structure of a virus?

A

•viruses are made up of nucleic acids
•the nucleic acids are surrounded by a protein called a capsid
•viruses are smaller than bacteria
•attachment glycoproteins

18
Q

What are viruses not considered as living ?

A

•they have no nucleus, plasma membrane, cytoplasm or ribosomes
• they are not made as cells
•they cannot reproduce independently

19
Q

What are the function of viruses?

A

1) to replicate, viruses have to invade and hijack the reproductive mechanism of a living cell
2) viruses have attachment glycoproteins that bind to complementary receptors on host cells
3) they then inject DNA or RNA into the host cell
4) the host cell divides as normal and the virus is replicated

20
Q

What is the definition of resolution?

A

How well a microscope can distinguish between two points close together

21
Q

What is the definition of magnification?

A

How much bigger an image from a microscope is compared to the specimen

22
Q

What are the principles of a optical (light microscope) ?

A

Light is directed on to a specimen using mirrors

23
Q

What is an advantage of a optical microscope?

A

•dead or alive specimens
•uses colour

24
Q

What is a disadvantage of a optical microscope?

A

Lower resolution and magnification

25
Q

What are the principles of a transmission electron microscope (TEM)?

A

Electromagnets focus a beam of electrons through a thin slice of specimen, denser parts of the specimen absorb more electrons than other parts

26
Q

What are the advantages of a TEM microscope?

A

•generates image on computer (false colour can be added after)
•resolution and magnification is good

27
Q

What are the disadvantages of a TEM microscope?

A

•only in black and white
•can only view dead specimens
•2D images only
•can contain artefacts

28
Q

What are the principles of scanning electron microscope ( SEM) ?

A

An electron beam is scanned across a specimen, knocks electron off the specimen and gather in a cathode ray tube to form a image

29
Q

What is an advantage of a SEM microscope?

A

•image shows the 3D surface
•generates image on a computer
•specimens do not have to be thin
•good resolution and magnification (but lower than TEM)

30
Q

What is a disadvantage of a SEM microscope?

A

•only in black and white
•dead specimens only
•can contain artefacts

31
Q

How do you measure the actual length of a specimen?

A

1) calibrate the eyepiece graticule (in eyepiece)
2) micrometer of known length on stage
3) line them up to work out the scale of divisions

32
Q

Why do electron microscopes have a higher resolution and magnification than light?

A

Electron microscopes have shorter wavelength

33
Q

What is the equation of magnification?

A

Magnification= size of image/actual size of specimen

34
Q

Describe the process of cell fractionation and ultracentrifugation.

A

1) homogenisation
First you blend/break up the cells to release organelles into a solution, this solution need to be ice cold to reduce the activity of the enzymes it also need to be isotonic to have the same water potential to prevent water from moving via osmosis and it also need to be buffered to prevent damage to the organelles, we are then left with a homogenised solution
2)Filtration
Homogenised cell solution is filtered through a gauze to separate large cell debris from organelles
3) Ultracentrifugation
Cell fragments are poured into a tube and then spun at a low speed, heaviest organelles are moved to the bottom of the tube to form a thick sediment called the pellet, the rest of the organelles dart suspended in the fluid above the pellet (supernatant), the process is repeated at higher and higher speeds until all the organelles are separated out

Aqa A-level Biology (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions