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Flashcards in Cell Structure Deck (46)
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1
Q

Eukaryotic cells

A

Complex cells e.g. Animal or plant cells.

Cells with a true nucleus

2
Q

Organelles in an animal cell?

A
  • Plasma membrane
  • Rough endoplasmic reticulum (RER)
  • Smooth ER
  • nuclear envelope
  • Nucleus
  • Nucleolus
  • Lysosome
  • Ribosome
  • Golgi apparatus
  • Cytoplasm
  • Mitochondria
3
Q

Organelles in a plant cell?

A
  • Cell wall with plasmodesmata
  • Vacuole
  • Plasma membrane
  • Chloroplast
  • RER
  • SER
  • Mitochondria
  • Golgi
  • Cytoplasm
  • Nuclear envelope
  • Nucleolus
  • Nucleus
  • Ribosome
4
Q

What organelles does a plant cell have that an animal cell does not?

A
  • A cell wall with plasmodesmata
  • Chloroplasts
  • Vacuole
5
Q

What organelles does an animal cell have that a plant cell doesn’t?

A

Lysosomes

6
Q

What is plasmodesmata?

A

Channels for exchanging substances with adjacent cells

7
Q

Function of plasma membrane

A
  • Regulates movement of substances in and out of the cell

- Has receptor molecules which allow cell signalling through means of chemicals

8
Q

Function of cell wall

A

-Supports plant cells

9
Q

Function of nucleus

A
  • Controls cell’s activities by controlling transcription of DNA
  • Contains DNA needed to make proteins
  • The pores allow substances (e.g RNA) to move between the nucleus and the cytoplasm
  • The nucleolus makes ribosomes
10
Q

Function of a lysosome

A
  • Contains digestive enzymes
  • Keeps the digestive enzymes separate from the cytoplasm by its surrounding membrane
  • Can be used to digest invading cells or break down worn out components
11
Q

Function of ribosomes

A

-The site where proteins are made

12
Q

Function of rough endoplasmic reticulum

A

-Folds and processes proteins that have been made in the ribosomes

13
Q

Function of the smooth endoplasmic reticulum

A

-Synthesises and processes lipids

14
Q

Function of a vesicle

A

-Transports substances in and out of the cell (via the plasma membrane) and between organelles

15
Q

Function of the Golgi apparatus

A
  • Process and package new lipids and proteins

- Makes lysosomes

16
Q

Function of the mitochondria

A

-Site of aerobic respiration where ATP is produced

17
Q

Function of chloroplasts

A
  • The site of photosynthesis

- Some parts of photosynthesis happen in the grana and others in the stroma

18
Q

Function of the centriole

A
  • Involved with the separation of chromosomes during cell division
  • Send out spindle fibres
19
Q

Function of cilia

A

-They move substances along the cell surface

20
Q

Function of the flagellum

A
  • It’s microtubules contract to make flagellum move

- Propel cell forward

21
Q

Where are mitochondria generally found?

A

In very active cells that require a lot of energy. They are found in large numbers.

22
Q

What is the name of the membrane inside the chloroplast called?

A

Thylakoid membrane

23
Q

What is grana?

A

Stacked up thylakoid membranes

24
Q

What are grana linked together by?

A

Lamellae

25
Q

What does the inner membrane of a mitochondrion fold to form?

A

Cristae

26
Q

Where are the enzymes for respiration in the mitochondrion?

A

Matrix

27
Q

Describe protein production in a cell

A
  • Proteins are made in the ribosomes
  • New proteins produced at the RER are folded and processed
  • Then transported from the RER to the Golgi apparatus in vesicles
  • At the Golgi apparatus the proteins may undergo further processing
  • The proteins enter more vesicles to be transported around the cell
28
Q

The four main functions of the cytoskeleton:

A
  • The microtubules and microfilaments support the cells organelles, keeping them in structure.
  • They help strengthen the cell and maintain its structure.
  • Responsible for movement of materials within the cell e.g. Movement of chromosomes during cell division
  • Proteins of the cytoskeleton can also make the cell move
29
Q

Features of prokaryotes

A
  • Extremely small-less than 2nanometer diameter
  • DNA is circular/loop
  • No nucleus, DNA is free in the cytoplasm
  • Few organelles but none are membrane bound
  • Flagellum (when present) made of the protein flagellin, arranged in a helix
  • Small ribosomes
30
Q

Features of eukaryotes

A
  • Larger cells- about 10-100 nm diameter
  • DNA is linear
  • Nucleus is present, DNA inside
  • Many organelles (membrane bound)
  • Flagella (when present) is made of microtubule proteins arranged in a ‘9+2’ formation
  • Larger ribosomes
31
Q

Magnification

A

The number of times larger an image appears, compared to the size of the object

32
Q

Resolution

A

The clarity of an image; the higher the resolution the clearer the image

How well a microscope can distinguish between two points

33
Q

How to calculate magnification of an image

A

Image size/object size

34
Q

Prokaryotic cell

A

Smaller, simpler cells e.g. Bacteria

Lack membrane bound organelles and an organised nucleus

35
Q

Name the 3 types of microscopes

A
  • Light microscope
  • Laser scanning confocal microscopes
  • Electron microscope-(TEM and SEM)
36
Q

Describe how a light microscope works

A

By using light to observe an image

37
Q

How high is the resolution of a light microscope?

A

0.2 micrometers approx. A lower resolution than electron microscopes so they are usually used to look at whole cells or tissue.

38
Q

Maximum magnification of a light microscope

A

x1500

39
Q

Describe how a Laser scanning confocal microscope works

A
  • Uses laser beams (intense beams of light) to scan a specimen, which is usually tagged with a fluorecent dye.
  • The laser causes the dye to fluorece
  • This light is then focused through a pinhole onto a detector
  • The detector is hooked up to a computer, which creates a 3D image
40
Q

How is sending the LSCM light through a pinhole useful?

A

It blocks out all the out of focus light so that these microscopes can get a clearer image than light microscopes.

41
Q

Descibe how an electron microscope works

A

Electrons are used to form an image instead of light.

42
Q

Why are electron microscopes better than light ones?

A

Because they have a higher resolution and can get a more detailed image.

43
Q

Describe how a Transmission electron microscope works

A
  • Uses electromagnets to focus a beam of electrons, which is then transmitted through the specimen.
  • Denser parts of the specimen absorb more electrons, which makes them look darker
44
Q

Positives and negatives of TEM’s

A
  • Provide high resolution images, so can be used to look at a wide range of organelles.
  • Can only be used to look at thin specimens
45
Q

Describe how a Scanning electron microscope works

A
  • They scan a beam of electrons across the specimen

- This knocks off electrons from the specimen, which are gathered in a cathode ray tube to form an image

46
Q

Describe the image produced by the SEM

A
  • Shows the surface of the specimen and can be 3D

- Gives a lower resolution than TEM’s