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Biology AL > Topic 2 > Flashcards

Topic 2 Flashcards

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1
Q

Name structure of eukaryotic cells that cannot be identified using an optical microscope

A 
ribosomes
lysosome
cell-surface membrane 
mitochondrion 
endoplasmic reticulum
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2
Q

What is the function of chloroplast

A

site of photosynthesis

some in grana some in stroma

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3
Q

Describe the structure of chloroplasts

A
  • Flattened structure surrounded by double membrane
  • stacked membranes (thylakoids) form grana
  • that are linked together by lamellae
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4
Q

What is the cell wall of Algal cells (algae) made of?

A

Chitin

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5
Q

What organelle is in a plant cell but not algal cells

A

chloroplast

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6
Q

what is the cell wall of plants made of

A

Cellulose

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7
Q

what is the function of cell wall

A
  • supports cell

- prevents cell from changing shape

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8
Q

what is the surrounding membrane of a cell vacuole called?

A

Tonoplast

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9
Q

Describe the cell vacuole

A
  • contains cell sap (solution of salts and sugars)
  • tonoplast as membrane
  • membrane-bound found in cytoplasm
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10
Q

what is the function of cell wall?

A
  • maintains pressure inside cell (keeping cell rigid)
  • isolates unwanted chemicals
  • some involved in digestion of pathogens/toxins
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11
Q

suggest and explain 2 ways sieve cells are adapted for mass transport

A
  1. Little cytoplasm and large vacuole
    - > so easier and more flow
  2. Thick walls
    - > to resist pressure
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12
Q

suggest a way in which companion cells are adapted for the transport of sugars between cells

A
  • have mitochondria that release ATP

- > for active transport

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13
Q

what is the function of nucleus

A

holds genetic information (DNA) of cell

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14
Q

describe SER

A
  • not covered with ribosomes

- smooth membranes enclosing fluid filled space

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15
Q

what is the function of SER

A

-synthesises and processes LIPIDS

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16
Q

Describe RER

A
  • covered with ribosomes

- membranes enclosing fluid-filled space

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17
Q

what is the function of RER

A

-folds and processes PROTEINS that were made at the ribosome

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18
Q

what is the cell surface membrane made of?

A

lipids and protein

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19
Q

what is the function of cell surface membrane?

A
  • regulates movement of substances into and out of cell

- has receptor molecules ->enables response to hormones/some chemicals

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20
Q

describe a mitochondrion

Study These Flashcards
A
  • double membrane: outer & inner

- folded structure: cristae (outer) & matrix (inner)

21
Q

what is the function of mitochondria?

Study These Flashcards
A

site of aerobic respiration (ATP)

22
Q

list 2 key features of mitochondria

Study These Flashcards
A
  • found in large numbers/quantity

- active and require a lot of energy

23
Q

list 3 functions of nucleus

Study These Flashcards
A
  • makes: ribosomes
  • controls transcription of DNA as it holds genetic information
  • pores allow substances (RNA) to move between nucleus and cytoplasm
24
Q

list 2 functions of lysosomes

Study These Flashcards
A
  • contain lysozymes that
  • > digest/break down worn out organelles
  • > digest/break down toxins
25
what are the 3 differences in DNA of eukaryotes vs DNA in prokaryotes
``` EUK: -DNA bound to protein, -DNA is linear -usually has introns PROK: -single circular DNA free in cytoplasm -usually no introns ```
26
Which is generally larger eukaryotes of prokaryotes?
eukaryotes (~10-100um) > prokaryotes (~1-5um)
27
how do prokaryotes reproduce?
binary fission | note: haploid [single chromosome]
28
how to eukaryotes reproduce?
- mitosis and meiosis | note: diploid or more [paired chromosomes]
29
order the following from inner to outer in bacteria | cell wall, capsule, plasma membrane
plasma membrane, cell wall, capsule
30
list 3 differences in organelles of eukaryotes vs prokaryotes
eukaryotes: - have nucleus - organelles are membrane bound - larger ribosomes (80s) prokaryotes: - no nucleus (single circular DNA free in cytoplasm) - organelles NOT membrane bound - 70s ribosomes - cell walls contain murein (glycoprotein)
31
order the following from inner to outer in virus: | matrix, attachment protein, reverse transcriptase, lipid envelope, capsid
reverse transcriptase, capsid, matrix, lipid envelope, attachment protein
32
Advantages and Disadvantages of an optical/light microscope compared to an electron microscope?
ADV: cheaper - uses light to form image Disadvantage: lower resolution - cannot see ribosomes, ER, Lysosomes limited maginification (max X1500)
33
Describe how you could make a temporary mount of a piece of plant tissue to observe the position of starch grains in the cells when using an optical/light microscope.
- add drop of water to glass slide [using pipette] - obtain thin section of plant tissue [using tweezers] - place on drop of water - stain with iodine dissolved in potassium iodide - lower cover at an angle [prevent air bubbles] - using mounted needle
34
Compare SEMS VS TEMS microscopes
SEMS shows surface of specimen -> 3D TEMS focuses beam of e- that are transmitted through specimen so denser parts of specimen absmorb more e- -> 2D SEMS lower resolution TEMS can present internal structures of organelles SEMS can be used on thick specimen TEMS can ONLY on thin specimens
35
what are artefacts and give examples?
- affect observation and result in inaccuracies | - dust, air bubbles, fingerprints, squashing, over/under staining
36
Define resolution
how well a microscope distinguishes between 2 points close together
37
what happens in interphase
- DNA unravelled and replicated -> genetic material doubled - organelles replicated - amount of ATP increase
38
what happens in Prophase
- chromosmes condense -> become visible - centrioles move to opp poles of cell, spindle fibres form - nuclear envelope breaks down -> chromosomes free in cytoplasm
39
What happens in Metaphase
- chromosomes line up along equator | - spindle fibres attahces to their centromere
40
what happens in Anaphase
-centromeres divide -> separating pair of sister chromatids -spindle fibres contract ->chromatids pulled to opp poles of cell by centromere {appear v shaped)
41
What happens in Telophase
- sister chromatids at opp poles uncil -> chromosomes - nuclear envelope forms 2 nuclei arond the 2 groups of chromosomes at opp poles - cytokineses: division of cytoplasm - >2 daughter cells genetically identical to parent cell and each other
42
Describe how bacteria multiply
- circular DNA replicated once - plasmids replicated 1 or more times - cytoplasmic membrane elongates - DNA loops -> moves to opp ends of poles - cytoplasm begins division - new cell wall begins formation -cytoplasm divides -2 daughter cells produced [each with 1 copy of circular DNA but variable no. of copies of plasmids]
43
what does a high mitotic index suggest?
- tissue repair occuring | - cancerous growth in tissue
44
…. has no cholesterol in its cell-surface membrane. Despite this, the cell maintains a constant shape. Explain why?
- cell has cell wall - made of murein - which provides rigidity - so cell unable to change shape
45
Describe how phospholips are arrange in a plasma membrane.
- bilayer - where hydrophobic tails to inside - hydrophilic head to outside
46
Define simple diffusion
- passive process - net movement of particles from area of higher concentration to area of lower concentration down a concentration gradient
47
what does rate of diffusion depend on
- SA, the larger the SA of cell-surface membrane,the faster the rate of diffusion - Concentration gradient, the higher the conc gradient, the faster the rate of diffusion - thickness of exchange surface, the thinner/shorter distance, the faster the rate of diffusion
48
Define facilitated diffusion
- passive process | - net movement of particles from area of higher conc to area lower conc down a conc gradient
49
How do channel proteins work?
- charged particles [ions/polar molecs] are water soluble - so diffuse slowly since centre of bilayer is hydrophobic - channel form pores in membrane for charged particles

Biology AL (4 decks)

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