Brainscape's Knowledge GenomeTM

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


See full index

AS Biology > Chapter 1: Cell Structure > Flashcards

Chapter 1: Cell Structure Flashcards

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

How many millimetres in a metre

A

1000mm

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

How many micrometers in a metre

A

10^6 Mm

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

How many nanometers in a metre

A

10^9 nm

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

How many metres in a Mm and nm

A

Mm- 10^-6 m

nm- 10^-9 m

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

What is magnification

A

Number of times greater an image is than an object

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

What is formula for magnifications

A

M=I/A

image/actual

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

What are cell organelles?

A

Structurally and functionally distinct parts of cells that have their own functions

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

Nucleus is enclosed by a _ made up of _ also called _

A

Double membrane
Outer and inner membranes
Nuclear envelope

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

Nucleus continues to form ER. What do these 2 aid in? (#4)

A

Ribosome, nucleotide, hormone, ATP production

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

What are the raw materials for protein synthesis in a non dividing cell

A

RNA

Ribosomes

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

What makes up the chromatin network? How does it behave during cell division?

A

Loosely coiled threads of DNA and proteins called histones

Condenses (wraps tightly around histones and coils further) to form chromosomes containing genes in DNA

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

Function of nucleolus?

A

Ribosomal factory with it’s own DNA and RNA

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

Function of nuclear pore :

A

Controls material exchange between nucleus and cytoplasm

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

What is transcription?

A

When DNA is converted to mRNA in nucleus

(gene switched on, RNA polymerase at promoter, unzipped gene, complementary RNA bases, modifications to remove noncoding regions)

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

What is translation?

A

When mRNA is converted to proteins in the cytoplasm/ribosomes

(ribosome reads, tRNA brings amino acids(20) each of 3 bases- codons, and form a chain)

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

ER has _ membrane

A

1

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

Appearance of rough ER + function:

A

Ribosomes present

Protein synthesis

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

Appearance of smooth ER + function:

A

No ribosomes

Lipid, cholesterol, steroid synthesis

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

A ribosome is a _

A

Non membrane bound organelle

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

Where are 70S ribosomes found?

A

Prokaryotes (bacteria), mitochondria, chloroplasts

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

Where are 80S Ribosomes found?

A

Eukaryotes

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

What are Ribosomes made of

A

rRNA

Proteins

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

What is the Svedberg unit and what does it depend on?

A

Measure of ribosome size

Rate of sedimentation in centrifuge

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

What are the functions of Golgi complex?

A

Collection
Modification
Sorting of proteins and lipids
And of course distribution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

How is a protein modified? Give 4 ways

A
  • Glycosylation- addition of glucose residue to form glycoprotein
  • Methionine amino acid group is removed to convert inactive protein to active one
  • Phosphorylation- addition of phosphate group
  • Protein folds into tertiary/quarternery protein
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

How are lipids modified? 2 ways

A

Glycosylation- giving glycolipid

Phosphorylation- giving phospholipid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Protein/lipid loaded vesicles from ER fuse with Golgi body at _ end and leave at _ end

A

Cis/forming end

Trans/budding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

The secretory pathway has 2 targets. Either _ or _

A

Other organelles eg lysosome

Cell membrane; vesicles fuse with it and contents are thrown out - exocytosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Lysosomes have _ and are a site of _

A

Hydrolytic enzymes

Intracellular digestion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

How do lysosomes breakdown 1)old organelles 2)damaged cells

A

1) organelle is unfolded by membrane into phagocytic vacuole, +enzymes, egestion
2) it breaks and spreads contents across cytoplasm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Sperm heads have _ for _

A

Acrosome

Destroy path to egg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

4 functions of lysosome

A

Old organelles breakdown
Old cells breakdown
Foreign disease organisms breakdown
Sperm head

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

pH of lysosome is

A

Acidic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Outer mitochondrial membrane is _ and consists of aqueous _ called _ which _

A

Permeable
Protein channels
Porins
Passes small water soluble molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

pH of intermitochondrial space is

A

Acidic (H+)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Inner mitochondrial membrane is _ and has folds called _ to increase _ for _

A

Semi permeable
Cristae
Surface area
Efficiency of respiration/ATP production

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

The matrix is site of

A

Krebs cycle/aerobic respiration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Where is Atp synthase found and it’s function?

A

Cristae

Atp synthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Mitochondria have _ ribosomes

A

70S

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Mitochondria are able to replicate because?

A

They have circular DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Function of mitochondria is

A

Acts as powerhouse for cells/ATP production

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Chloroplasts are site of

A

Light reactions of photosynthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

State chloroplasts membranes and eachs nature

A

Envelope made of
Outer- permeable
Inner- semipermeable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Why can chloroplasts self replicate

A

Have own circular DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What is the matrix of a chloroplast? It’s the site of?

A

Stroma

Dark reactions of photosynthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

State the main structures in chloroplasts which capture light

A

Grana are stacks of thylakoids which house chlorophyll pigment and electron carriers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

Light reactions produce - and - which provide raw material for - and the end product is -

A

ATP
NADPH
Dark reaction
Starch

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

What is the Endosymbiotic Theory?

A

Eukaryotic cell originated from a symbiotic relationship among prokaryotes
Free living Prokaryotes such as ancestral aerobic/photosynthetic bacteria began living inside eukaryotes and were modified as to be useful to the host cell and make it efficient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

Why can mitochondria and chloroplasts now not grow outside host cells?

A

They lost cell walls and much of DNA

They aren’t likely to adapt too quickly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

3 evidences for Endosymbiosis?

A

Like bacteria;

  • chloroplasts and mitochondria divide by binary fission
  • own circular DNA
  • own 70S ribosomes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

What is cell membrane made of

A

Phospholipids + transport proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

Function of cell membrane?

A

Controls substance exchange between cell and it’s environment ie boundary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

Nature of cell membrane is

A

Semipermeable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

2 modifications of cell membrane with regard to microvilli

A

They increase surface area of small intestine for absorption of digested food

Line pct of nephron for maximum reabsorption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

1 microtubule made of _ _

A

13 protofilaments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

Protofilaments are made of

A

Tubulin proteins; α and β, which together form a dimer by polymerisation . This dimer is a helical ring with hollow centre

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

Where does assembly (polymerisation) and disassembly of microtubules occur?

A

MTOC

microtubule organizing centre

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

How are MTOC in animal cells

A

Centrosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

How are MTOC in plant cells

A

Absent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

How are MTOC in organisms having cilia and flagella ie beating movements

A

Centriole OR basal body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

3 functions of microtubules?

A
  • acts like a cytoskeleton holds cell in place
  • intracellular transport ie movement of organelles, vesicles to organelles
  • form spindle fibres for separation of chromosomes during cells division
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

State the composition of centrosome and Centriole

A

Centrosome : 2 centrioles perpendicular

Centriole : 9+0 arrangement of 9 microtubule triplets

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

Location of microtubules

A

Cytoplasm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

What are Paramecium

A

Unicellular ciliate

Moves and sweeps prey using cilia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

What are Euglena

A 
Unicellular flagellate (2 flagellae)
Motor to push through water
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

How do plants produce spindle fibres

A

MTOC in centrosome region

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

Nature of cell wall

A

Freely permeable

68
Q

Plant cell wall made of

A

Cellulose

69
Q

What are plasmodesmata

A

Cytoplasm strands linking adjacent plant cells

70
Q

What is middle lamella

A

Sticky substance made of calcium pectate cementing adjacent plant cells together

71
Q

2 functions of cell wall

A

Gives cell shape

Prevents cell from bursting when water enters by osmosis

72
Q

Functions of vacuole

A

1) Regulates osmotic properties or cell by controlling water movement inside and outside the cells
2) Stores pigments, sugars, minerals, O2, CO2, waste substances and enzymes

73
Q

State vacuole size and no in plants and animals

A

Plants: one big central v
Animals: many small vs

74
Q

What is a tonoplast

A

The surrounding membrane of vacuole which is semipermeable and controls exchange in and out of it

75
Q

What are isotonic, hypotonic, hypertonic

A

Iso : same concentration no net change
Hypo : solution is less concentrated water flows into cell and swells (no burst in plants)
Hyper : solution more concentrated water flows out and cell shrinks (in plants flaccid and plasmolysis)

76
Q

What’s the size of the nucleus?

A

10-20 Mm diameter

77
Q

What’s the size of the nucleus?

A

10-20 Mm diameter

78
Q

What’s the size of the nuclear pore?

A

40-100 nm

79
Q

What’s the size of the chloroplast?

A

3-10 Mm

80
Q

What’s the size of the mitochondria?

A

1-10 Mm

81
Q

What’s the size of the ribosome?

A

20-25 nm

82
Q

What’s the size of the nucleolus?

A

1 Mm

83
Q

What’s the size of the lysosome?

A

0.1-1.2 Mm

84
Q

What’s the size of the Centriole?

A

0.5 Mm

85
Q

What’s the size of the cell membrane?

A

7 nm thickness

86
Q

State virus composition

A

Nature: Nucleic acid (DNA/RNA)

Protein coat called capsid made of smaller subunits ie capsomeres

87
Q

DNA has - strands

RNA has - strands

A

2

1

88
Q

Nature of virus:

A

Parasitic, only active inside living organisms bodies

89
Q

How do viruses reproduce?

A

Genetic material takes over protein synthesis machinery of host to reproduce virus particles (fuses with host dna, produces altered virus mrna and hence translates it’s own proteins)

90
Q

5 differences between plant and animal cells:

A

1) cell wall in plants only
2) chloroplasts in plants only for photosynthesis
3) large permanent central vacuole in plants, many small in animals
4) centrioles centrosomes present in animals only
5) plasmodesmata and middle lamella in plants only

91
Q

Similarities between plant and animal cells

A

cell membrane, nuclei, mitochondria, golgi, ER present

92
Q

What is in folding of cell membrane in prokaryotes called and what’s it’s function (#3)

A

Mesosome

Increase surface area for: respiration/photosynthesis/nitrogen fixation

93
Q

Prokaryotes DNA is

A

Circular ring and free lying

94
Q

Prokaryotes only have plasmids. What are they and what are 2 functions

A

Extrachromosomal circular DNA

Responsible for antibiotic resistance in bacteria and used in genetic engineering as a gene vector

95
Q

What does bacteria cell wall contain?

A 
Murein
A peptidoglycan (protein+carbohydrate)
96
Q

Nature of prokaryotes cell membrane is

A

Semipermeable

97
Q

What are pili on prokaryotes used for?

A

Attachment to surfaces, or other cells for sexual reproduction

98
Q

What and where is capsule of prokaryotes

A

Additional protection

Surrounding cell wall

99
Q

Which structures are always present in prokaryotes

A 
Circular DNA 
Cell wall
Cell membrane 
Cytoplasm
70S ribosome
100
Q

Compare the diameter of prokaryotes and eukaryotes

A

P- 0.5-5Mm

E- 40Mm, and 1000-10,000× the volume

101
Q

Compare the DNA shape, structure and location in P and E

A

P- circular, naked, free in cytoplasm

E- linear, proteins(histones)+DNA giving chromosomes, double membrane nucleus

102
Q

Compare ribosome size in P and E

A

P- smaller 70s, 20nm diameter

E- larger 80s, 25nm diameter

103
Q

Compare ER in P and E

A

P- not present

E- present, may have ribosomes

104
Q

Compare types of organelles present in P and E in terms of compartmentalization and division of labour

A

P- no membrane bound organelles unless formed by infoldings of cell membrane
E- single, double or no membrane bound organelles

105
Q

Compare examples of organelles in P and E

A

P- ribosome, microtubules, centriole (no membrane)
E- lysosome, golgi, vacuole, ER (single)
- nucleus, mitochondrion, chloroplast (double)
- ribosome, microtubule, centriole (no membrane)

106
Q

Compare cell walls in P and E

A

P- made of murein, a peptidoglycan (Polysaccharide+amino acids)
E- plants- cellulose/lignin
- fungi- chitin (nitrogen containing polysaccharide like cellulose)

107
Q

What is a microscope

A

It helps visualise very small objects that cannot be seen with the naked eye

108
Q

State the source of illumination for a light microscope

A

Light

109
Q

What is the resolution of light microscope and why is it significant

A

200nm

Any object with less less than 200nm cannot be seen using a light microscope because it cannot block light waves

110
Q

State and explain each of the 3 lens in a light microscope

A

Condenser lens: focuses light onto specimen on slide
Objective lens: collects light passing through specimen and produces magnified image
Eye piece lens: magnifies and focuses image from objective lens onto eyev

111
Q

What is light microscope lens made of

A

Glass

112
Q

What stain is used for light microscope

A

Colored dye

113
Q

Why are objects stained?

A

If transparent light passes through and won’t be visible. And the dye each part of a cell retains will make it easy to identify separate parts eg nucleus holds more so less light passes hence darker compared to cytoplasm

114
Q

Source of illumination for Electron microscope ?

A

Electron beam

115
Q

State and explain each of the 3 lens in a electron microscope

A

Condenser lens: focuses light onto specimen on slide
Objective lens: collects light passing through specimen and produces magnified image
Projector lens: focuses magnified image onto screen

116
Q

What are EM lens made of

A

Electromagnet

117
Q

What stain is used in EM

A

Heavy metal

Stops electron passage

118
Q

Why can only dead specimen be seen using EM, unlike LM

A

Specimen need to be dehydrated ie dead because water boils at room temp in a vacuum and can hinder view under EM

119
Q

Why is specimen kept in vacuum in EM?

A

Prevent collision of electrons and air molecules

Which would scatter prevent a sharp picture

120
Q

Compare resolution of SEM with TEM

A

TEM is higher
SEM - 0.5nm
TEM- 0.05nm

121
Q

State the difference between how SEM and TEM work

A

SEM - reflected electron beam forms image

TEM - transmitted electron beam firms image

122
Q

What can SEM and TEM help in viewing

A

SEM - cell surface structure

TEM - internal structure

123
Q

What is resolution?

A

Ability of a microscope to distinguish between 2 objects very close together. The higher the resolution, the greater the detail that can be seen

124
Q

What is formula for resolution

A

Lambda/2 where lambda is wavelength of light source

125
Q

What is the electromagnetic spectrum?

A

Whole range of wavelengths

126
Q

Relate wavelength to frequency

A

Lambda = 1/V(frequency)

127
Q

Relate frequency and wavelength to energy

A

V α E greater the frequency, greater the energy

Shorter the wavelength, greater the energy

128
Q

Electrons and light are both forms of -

A

Radiation

129
Q

Cell surface membrane is also called -

A

Plasma membrane

130
Q

What is DNA

A

Molecule containing instructions that control cell activities

131
Q

What is nucleolus

A

Made of loops of DNA from several chromosomes

132
Q

What is the cytoplasm

A

Aqueous material between nucleus and cell surface membrane

133
Q

What is compartmentalization and why is it important

A

Organelles are surrounded by membranes so their activities are separated from the cytoplasm
Efficiency

134
Q

What does it mean when a cell shows division of labor?

A

Sharing of work between different specialised/function organelles

135
Q

What is function of chlorophyll/in chloroplast

A

Absorbs light during photosynthesis

136
Q

2 differences between cell wall and cell membrane?

A

Wall is thick, membrane is thin

Wall is freely permeable, membrane is partially

137
Q

What is an eye piece graticule

A

Transparent scale with 100 divisions. Used in microscope eyepiece so it can be seen along with object

138
Q

How is eyepiece graticule calibrated

A

A small transparent ruler with subdivisions (0.1-0.01mm) called stage micrometer is placed on the microscope stage and superimposed with graticule

138
Q

How is eyepiece graticule calibrated

A

A small transparent ruler with subdivisions (0.1-0.01mm) called stage micrometer is placed on the microscope stage and superimposed with graticule

139
Q

Formula or what ever for calibrating value of 1 eyepiece unit

A

x mm of stage micrometer in y eyepiece units/100

this value× no of eye piece units gives actual size of object

140
Q

To convert from mm to Mm you should?

A

×1000

141
Q

How to calculate magnification using scale bar?

A

Measure scale bar (observed)
Convert to Mm
Divide by given scale bar length (A)

142
Q

What’s photomicrograph/electron micrograph

A

Image from light microscope/electron micrograph

143
Q

If 2 objects are closer than 200nm they can’t be seen as separate points on a -?

A

Light microscope

144
Q

How does the brain distinguish between visible light wavelengths

A

Converts them to colors

145
Q

All waves travel at the same

A

Speed

146
Q

What is the maximum magnification of light microscope

A

1500

147
Q

Why is 200nm the best resolution of LM

A

The smallest wavelength is 400nm of violet, and half of radiation is the limit of resolution. Hence <200nm cannot be seperately from nearby objects

148
Q

State types of radiation in increasing wavelength

A 
Gamma
Xray
Ultraviolet 
Visible light 
Infrared 
Microwaves 
Radio waves
149
Q

Why are electrons suitable for microscopy

A

Wavelength is very short so resolution can be very small
They are negatively charged and can be focused easily using electromagnets (alters beam path) in comparison with similar wavelength xray hard to focus

150
Q

How are electrons produced for microscopy

A

Metal heated. Energy gained by electrons and escape orbits

151
Q

1 advantage and disadvantage of SEM

A

Specimen is in focus and a 3d picture achieved at the same time

Resolution not as good as TEM

152
Q

What is ultrastructure

A

Fine structure of a cell as revealed by an EM

153
Q

ER and golgi have an extended system of flattened sacs called _

A

Cisternae

154
Q

What is a golgi body

A

Constantly forming and broken stack of cisternae and it’s vesicles

155
Q

Golgi enzymes convert sugars in plants to

A

Cell wall components

156
Q

Golgi vesicles are used to make digestive organelles called

A

Lysosomes

157
Q

Lysosome structure :

A

Spherical sac
Single membrane
Hydrolytic enzymes inside

158
Q

The inner mitochondrial membrane is a selective barrier meaning

A

Controls what ions and molecules enter matrix

159
Q

Function of mitochondria

A

Aerobic respiration

160
Q

3 organelles with envelopes/double membrane

A

Nucleus
Mitochondria
Chloroplast

161
Q

Lipids in chloroplasts are used for

A

Making membranes of from breakdown of membranes

162
Q

Group containing most unicellular eukaryotes :

A

Protoctists

163
Q

3 principles of modern cell theory :

A

Basic unit of life is cell
All living organisms are made of cells
Cells arise from preexisting cells

164
Q

Formula to convert millimetres to micrometers

A

mm/0.0001

165
Q

Organelles with no membranes

A

Ribosome
Centriole
Microtubule

166
Q

Organelles with single membrane

A

Lysosome
ER
Golgi

AS Biology (11 decks)

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