Cells Flashcards

1
Q

What is the preparation stage

A

Tissue was placed in … solution
Cold = prevent enzyme activity
Isotonic (same con.) = prevent osmosis
Buffered = maintain a constant pH

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2
Q

What is the homogenisation stage

A

Tissue is placed in the blender = break up cell
Then fluid is extracted (homogenate)
And filtered = remove whole cells and debris

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3
Q

What is ultracentrifugation

A

Homogenate is placed in an ultra centrifuge
Spun at low speed = creates a density gradient
Sediment in the base and supernatant at the top
Extract supernatant
Repeat with medium and high speeds

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4
Q

What is the supernatant

A

The solution at the top of the homogenate that is collected ( contains cell organelle)

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5
Q

What order are cell organelles collected from cell fractionation

A

Nuclei
Mitochondria
ribosomes

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6
Q

What are the features of a light microscope

A
Uses light
Long wavelength
Low magnification
200nm resolution
In colour 
2D
Not in a vacuum
Thin sample-single layer 
No complex staining
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7
Q

What are the features of TEM (transmission electron microscope)

A
Uses electrons
Short wavelength
High(est) magnification
0.1nm resolution
Not in colour
2D
Thin samples 
In a vacuum
Complex staining
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8
Q

What are the features of an SEM (scanning electron microscope)

A
Uses electrons
Short wavelength
High magnification
10–20nm resolution
Not in colour
3D
Thin sample
In a vacuum
Complex staining
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9
Q

What is cell fractionation

A

A method to remove the organelle from cells

  1. Preparation
  2. Homogenisation
  3. Ultracentrifugation
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10
Q

How do you work out magnification

A

Size of object

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11
Q

Role of cell wall

A

Gives structure

Stops cell collapsing

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12
Q

Role of chloroplast

A

Site of photosynthesis

Absorb light

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13
Q

Role of smooth endoplasmic reticulum

A

Forming and transporting lipids

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14
Q

Role of Mitochondria

A

Produces ATP-> leads to energy release

Double membrane
Matrix- produces lipid fluid
Lots of enzymes
Cristae- LSA

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15
Q

Role of Ribosomes

A

Protein synthesis

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16
Q

Role of nucleus

A

Makes RNA and ribosomes

17
Q

Roles of lysosomes

A
Contains enzymes 
Digests substances (Eg. Old non-useful structures)
18
Q

Role of Nuclear pores

A

Allows passage of large molecules (mRNA)

19
Q

Role of nucleoplasm

A

Contains chromotin

20
Q

Role of rough endoplasmic reticulum

A

Contains ribosomes

Forming and transporting proteins

21
Q

Roles of Golgi body

A

Modified proteins
Makes glycoproteins
Produces secretory enzymes
Secretary carbohydrates

22
Q

Role of Golgi vesicles

A

Contains enzymes

23
Q

Role of cell membrane

A

Controls movement of substances in and out of cells

24
Q

Role of cytoskeleton

A

Transporting

Structure

25
Q

Role of the pilli

A

Exchange of substances

26
Q

Role of flagella

A

Used for movement

27
Q

Role of cell wall

A

Structure

28
Q

Features of a eukaryotic cell

A
Cell wall 
Cytoskeleton
Cell membrane 
Golgi vesicles 
Golgi body 
Rough and smooth endoplasmic reticulum 
Mitochondria 
ribosomes 
Centrioles 
Nucleus 
Lysosomes 
Nucleus pores 
Nuclear 
Nucleoplasm 
Chloroplast 
Vacuole
29
Q

Features of a prokaryotic cell

A
Slime capsule 
Cell wall 
Cell membrane 
Nucleoid 
Pili 
Ribosomes 
Flagella 
Plasmid 

Very few organelles
Smaller ribosomes
No membrane-bound organelles

30
Q

Features of a cell surface membrane

A
Glycoprotein
Glycolipid
Extrinsic protein 
Intrinsic protein 
Cholesterol 
Phospholipids 
Hydrophilic head 
Hydrophilic tails
31
Q

Role of glycoproteins

A

Cell recognition and interaction

Hormones attach

32
Q

Role of extrinsic proteins

A

Molecules bind and pass through cell

33
Q

Role of intrinsic proteins

A

Allows large and charged molecules to pass through

34
Q

Role of cholesterol

A

Provides structural support

35
Q

Role of phospholipids

A

Allows lipid soluble substances in/out of cell

36
Q

What is the fluid-mosaic model

A

Individual phospholipids can move relative to each other

Proteins embedded in phospholipid layer