Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Cell Biology > Introduction to Cell Biology – Structure and Function of the Cell > Flashcards

Introduction to Cell Biology – Structure and Function of the Cell Flashcards

1
Q

What are the three principles of cell theory?

A
  • Cells are the fundamental units of life
  • All organisms are composed of cells:
  • All cells come from pre-existing cells:
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Describe the principle Cells are the fundamental units of life:

A

The principles that underlie the functions of the single celled bacterium are similar to those governing the 60 trillion cells of your body.

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

Describe the principle All organisms are composed of cells

A

Life is continuous, arising from other cells.

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

Describe the principle All cells come from pre-existing cells.

A

The origin of life on Earth was marked by the origin of the first cells.

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

Prokaryotic cells include…

A

…all bacteria and possess a simpler structure than eukaryotic cells.

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

What are prokaryotic cells?

A

Cells with no defined nucleus

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

What is the function of the plasma membrane in prokaryotes?

A

separates the external environment from the internal cytoplasm. It creates an impermeable barrier to most molecules.

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

What is the function of the cell wall in prokaryotes?

A

Cell wall provides strength and rigidity: but permeable to many small molecules

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

Eukaryotic cells include…

A

…all plants and animals as well as many single celled organisms: algae, amoebae, fungi and moulds. (Eukaryotic – cells with a true nucleus)

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

Unlike prokaryotes, eukaryotic cells contain…

A

…extensive internal membranes that define a collection of subcellular structures – organelles

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

The cytoplasm of eukaryotes also contains…

A

…a network of fibres called the cytoskeleton, which give the cell strength and rigidity and also control movement within the cell.

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

Plant cells are surrounded by…

A

…a rigid cell wall and contain a large membrane bound vacuole and chloroplasts.

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

Despite their differences, prokaryotic and eukaryotic cells have many …

A

…biochemical pathways in common – thus believed to have descended from the same ancestral cell.

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

Size of prokaryotes?

A

2um (2x10-6m)

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

Amount of dna in prokaryotes?

A

1.36 mm

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

Number of genes in prokaryotes?

A

4377

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

DNA organisation of prokaryotes?

A

1 circular chromosome in nucleoid

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

Size of eukaryotes?

A

10 – 100 mm
(1x10-5 – 1x10-4 m)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Amount of DNA in eukaryotes?

A

990 mm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Number of genes in eukaryotes?

A

30-38000

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

DNA organisation of eukaryotes?

A

2 or more chromosomes in membrane bound nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

The scale in microscopy is…

A

…logarithmic. Each unit is 10 times bigger than the previous unit.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Describe how Standard Light Microscopy: The compound microscope works.

A

Uses UV-visible light and several lenses to magnify the image of a specimen under study.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Describe how Electron microscopy (EM): transmission EM/ scanning EM works.

A

Fundamental principles similar to light microscopy except electromagnetic lenses focus a high velocity electron beam under high vacuum.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Example of microscope of standard light microscopy?
The compound microscope
26
Example of microscope of electron microscope.
transmission EM/ scanning EM
27
WHats the resolving power of the compound microscope (bright-field microscopy)?
0.2um (1 x 10-7 m)
28
Describe Confocal and Immunofluorescence microscopy
Fluorescent antibodies ‘stain’ specific organelles/structures within the cell. Confocal scanning microscope (which looks at a single focal plane) creates much sharper images.
29
Describe Time-Lapse Microscopy.
- Saccharomyces cerevisae - Treated with a-mating factor - Picture taken every 3 minutes for 16 hours.
30
In Electron microscopy (EM): transmission EM / scanning EM...
...Heavy metal stains scatter (diffract) the electrons and appear dark in the image
31
Describe Transmission electron microscopy
- Passes an electron beam through a sample. - Very thin samples (50-100nm) need to be prepared and stained with heavy metals (gold / osmium).
32
Resolving power of Transmission electron microscopy?
50pm (5 x 10-11 m)
33
Describe Scanning electron microscopy
Sample is coated with a thin layer of heavy metal (platinum) and the electron beam scans the surface. The image is formed from secondary electrons given off by the sample.
34
Resolving power of Scanning electron microscopy.
Resolving power: 10nm (1 x 10-8 m)
35
The plasma membrane forms...
...the boundary between the external and internal environment of the cell.
36
What is the phospholipid bilayer comprised of?
- Hydrophilic phosphate head groups. - Hydrophobic lipid tails
37
Describe the Hydrophilic phosphate head groups
orientate toward the aqueous internal / external environments
38
Describe Hydrophobic lipid tails
orientate towards each other.
39
The phospholipid bilayer / plasma membrane contains...
...proteins embedded in the membrane: integral membrane proteins
40
Plasma membrane is ...
...impermeable to most molecules except CO2, O2 and water
41
What is the nucleus surrounded by?
Surrounded by a double membrane
42
Describe the inner membrane of the nucleus' double membrane?
Inner: defines the nucleus
43
Describe the outer membrane of the nucleus' double membrane?
Outer: continuous with rough endoplasmic reticulum (ER)
44
What is the nucleolus?
nuclear organizer, RNA / Ribosome synthesis occurs here.
45
What do the nuclear pores do?
Nuclear pores serve as channels regulating the movement of material between the nucleus and the cytoplasm
46
What does the chromatin do?
combination of DNA and protein
47
What does the Nucleoplasm do?
equivalent to the cytoplasm but in the nucleus – nucleotides and enzymes are dissolved in here.
48
What is the The Endoplasmic Reticulum (ER)?
Interconnected network of internal membranes, responsible for the synthesis of membrane lipids and protein destined for other organelles, membranes and secretion.
49
THere are two types of endoplasmic reticulum which are...
Rough Endoplasmic Reticulum and Smooth Endoplasmic Reticulum
50
What is the Smooth Endoplasmic Reticulum?
site of fatty acid and phospholipid synthesis
51
Why is the rough endoplasmic reticulum rough?
its studded with ribosomes, hence the rough appearance.
52
Proteins from the rough ER move by ...
...transport vesicles to the Golgi apparatus, where further processing of the protein occurs.
53
Golgi has three defined regions...
- Cis (same) - Medial (middle) - Trans (away)
54
What does the golgi sort?
the golgi sorts proteins so that they end up at their correct cellular destinations by recognising ‘tags’ encoded within the protein.
55
The mitochondrion is known as...
...The ‘power plant’ of the cell
56
The mitochondrion completes...
the aerobic degradation of glucose
57
Respiration equation?
C6H12O6 + 6 O2 ---> CO2 + H2O + ENERGY
58
Most eukaryotic cells contain many...
...mitochondria
59
Mitochondria have a...
...double membrane
60
Function of the inner membrane of the mitochondrial double membrane?
impermeable and has a large number of foldings called cristae.
61
Why is the double membrane of the mitochondrial double membrane permeable?
permeable due to presence of porins (proteins that allow the passage of small molecules)
62
Mitochondria also contain its...
...own DNA (mitochondrial DNA), located in the matrix.
63
The Lysosome contain a...
...battery of degradative enzymes.
64
The Lysosomes are...
...Acidic with a pH of 5
65
Function of lysosomes?
- Help to break down complex DNA, proteins, lipids etc into their component parts. - Also breakdown organelles that have outlived their usefulness.
66
Where is The Peroxisome found?
Found in animal and plant cells.
67
What does the peroxisome contain?
- Contain enzymes that break down fatty acids and amino acids and as a by-product generate hydrogen peroxide (H2O2) - Many peroxisomes contain a crystalline array of catalase.
68
How is hydrogen peroxide neutralised?
This potentially damaging chemical is neutralized by large amounts of catalase within the peroxisome.
69
the chloroplast is...
...the site of photosynthesis
70
What is the chloroplast surrounded by?
Surrounded by a double membrane - - Inner: impermeable - Outer: permeable to small molecules
71
Describe internal membrane of chloroplasts
Further extensive internal membrane system made of thylakoid vesicles arranged in stacks called grana.
72
Thylakoid vesicles contain ...
...chlorophyll and other pigments
73
In chloroplasts, a space called the stroma surrounds ...
...the grana
74
Chloroplasts (like mitochondria) contain ...
...their own dna.
75
It was orignally thought that the cytosol was...
...a soup
76
Cytosol is the site of...
...glycolysis.
77
THe cytosol is high in...
...protein concentration
78
The cytosol contains...
...glycogen (storage granules)
79
How many classes of fibres in the cytoskeleton?
three
80
What are the different classes of fibres in the cytoskeleton?
1) Microtubules: 2) Microfilaments 3) Intermediate filaments - These help to maintain cell shape and mobility
81
Cilia and Flagella are...
...Motile extensions of the plasma membrane
82
What runs through the cores of cilia?
Microtubule filaments run through the cores of cilia
83
Function of flagella?
Flagella are used to propel the cell, e.g. bacterium or sperm cell.
84
Function of cilia?
Cilia beat back and forwards, flagella rotate
85
What kind of membrane do vacuoles have?
Semi-permeable membrane
86
Describe semi-permeable membrane
Permeable to water, but Impermeable to small molecules contained within the vacuole.
87
Describe formation of turgor.
entry of water causes the vacuole to expand, creating a turgor inside the cell, balanced by the rigidity of the cell wall.
88
The vacuole stores:
Water Ions Waste products Food materials (sucrose) Excess nitrogenous compounds (amino acids)
89
Whats the cell wall in plant cells used for?
- Impart strength and rigidity under turgor pressure. - It contributes to plant form by growing as the plant cells expand.
90
Whats the cell wall in plant cells composed of?
Primarily composed of cellulose (polysaccharide of glucose sugar) or lignin (complex polymer of phenolic compounds).
91
Thje cell wall in plant cells acts as a...
A physical barrier to many fungi, bacteria and other organisms that may cause disease.
92
THe cell wall of plant cells may also contain?
May also contain waxes to prevent plant tissues and proteins from drying out.
93
A variety of proteins and polysaccharides form ...
...specific contacts and junctions between cells.
94
The Extra-cellular Matrix imparts...
...strength and rigidity to multicellular tissues.
95
What are connective tissues?
extracellular spaces between cells consisting mainly of collagen
96
The connective tissue is rich in...
...rich in proteoglycans - form the ground substance in which collagen and other connective tissue fibres are embedded.

Cell Biology (19 decks)

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