CELLS Flashcards
(111 cards)
1
Q
What are the functions of the cytoskeleton? (4)
A
-provide mechanical strength to the cell.
-aid in movement within the cell.
-help move some cells (flagella, pseudopodia)
-movement outside the cell (cilia).
2
Q
What is a cytoskeleton? (1)
A
Is made of protein fibres.
3
Q
What does RER stand for? (1)
A
Rough endoplasmic reticulum.
4
Q
What is the function of RER? (1)
A
Involved in protein synthesis and post translational modifications.
5
Q
What does SER stand for? (1)
A
Smooth endoplasmic reticulum.
6
Q
What is the function of the nucleolus? (1)
A
To produce and assemble the cells ribosomes.
7
Q
What are some examples of double membrane bound organelles? (2)
A
The nucleus and mitochondria.
8
Q
What is the function of the cell membrane? (1)
A
Controls what enters and leaves the cell.
9
Q
Where can DNA be found in an animal? (2)
A
The nucleus and mitochondria.
10
Q
What is the function of the cytoplasm? (2)
A
Site of chemical reactions.
-holds the cells organelles
11
Q
What are some examples of eukaryotic cells? (4)
A
-animal
-plant
-fungi
-protoctists
12
Q
What is a eukaryotic cell? (1)
A
Contains DNA in a membrane bound nucleus, separate from the cytoplasm it also contains other membrane bound organelles.
13
Q
What is the Golgi apparatus? (2)
A
-a stack of 4-8 membrane bound sacks located near the nucleus.
-principal is tat of secretion from the cell.
14
Q
What is the mitochondria? (1)
A
Are trod shaped organelles in which they are a site of respiration which provides energy to the cell.
15
Q
What is the RER? (1)
A
Is studded with ribosomes.
16
Q
What is the plasma/cell membrane? (1)
A
Separates contents of the cell from the external environment, it is very thin.
17
Q
What is the cytoplasm? (1)
A
Jelly like substance and contains organelles.
18
Q
What are lysosomes? (2)
A
Membrane bound organelles that contain digestive enzymes.
19
Q
What do the enzymes in lysosome do? (4)
A
-destroys aging organelles.
-killing of bacteria
-extracellular actions of lysosomes.
-destruction of the cell.
20
Q
What is the nucleus? (1)
A
Large spherical or oval organelles surrounded by a double membrane called the nuclear envelope.
21
Q
What is the nucleolus? (1)
A
They are rounded, dark staining bodies located in the nucleus.
22
Q
Which organelles appear only in animal cells? (2)
A
-centrioles
-lysosomes
23
Q
What is the function of the nucleolus? (1)
A
Makes RNA and ribosomes no membrane).
24
Q
What happens at the RER? (1)
A
Proteins are synthesised at the ribosomes and engulfed at the reticulum.
25
What is the function of centrioles? (2)
-not membrane bound
-involved in cell division )mitosis and meiosis)
26
What are the differences between a plant cell and animal cel? (7)
-peroxlsome
-plasmodesmata
-chloroplast
-vacuole
-cell wall
-cytoskeleton
-chlorophyll
27
What is the function of the cell wall? (1)
Gives cell structure and keeps it turgid.
28
What is the cell wall? (1)
Is made of cellulose and surrounds the cell.
29
What is the function of the permanent vacuole? (1)
Is important in keeping the cell firm (when the cell is full of sap it is said to be turgid).
30
What is meant by ‘sap’ in a permanent vacuole? (1)
A watery solution of different substances including sugars, enzymes and pigments.
31
What is the permanent vacuole? (1)
Consists of membrane called the Tonoplast, filled with cell sap.
32
What are the similarities between animal and plant cells?(9)
-smooth ER
-nucleus (nuclear membrane/pores)
-Rough ER
-cell membrane
-vesicle
-mitochondria
-cytoplasm
-ribosomes
-Golgi apparatus
33
What is the function of chloroplasts? (1)
Site of photosynthesis
34
Where are chloroplasts present? (1)
All green plants.
35
What do chloroplasts do? (1)
Use carbon dioxide, water and light energy to build sugars.
36
What is a chloroplast? (3)
-surrounded by a double membrane.
-filled with a liquid called he storma.
-contains stacks of thylakoid membranes called grona.
37
What are unicellular organisms? (1)
Organisms that are made of a single cell.
38
What is an example of a unicellular organism? (2)
-amoeba
-e-coli
39
What is a multi cellular organism? (1)
Composed of many cells, usually the cells differentiate to become arranged into tissues, organs and systems.
40
What is differentiation? (1)
Te developmental process by which the structure of the cells of a multi cellular organism specialise.
41
What is a tissue? (1)
A group of cells that have a common origin and a similar structure that work together to perform a single function.
42
What is an organ? (1)
A structure, made of more than one type of tissue, that as a specific function e.g. the heart
43
What is an organ system? (1)
A group of organs and tissues that collectively perform a particular function e.g. circulatory system.
44
How are red blood cells specialised to carry out their function? (4)
-have a biconcave shape
-filled with haemoglobin, binds with oxygen molecules.
-has no organelles, not even a nucleus. Give it more space to carry oxygen.
-shape increases surface area for oxygen absorption.
45
How is a secretly epithelial cell specialised to carry out its function? (4)
-contains normal animal organelles.
-has many secretory vesicles.
-organised in a specific way
-contain many SER
46
What are plasmodesmata? (1)
Gaps in the cell wall in which plants exchange substances.
47
What is the structure of the nucleus? (4)
-surrounded by a double nuclear membrane that contains pores, these allow movement of molecules between the cytoplasm and the nucleus. E.g. the movement of mRNA.
-contains chromosomes, appear dispersed as a diffuse network called chromatin.
-the presence of one or more nucleoli, the site of ribosome synthesis.
48
What is a nucleoli? (1)
A singular nucleolus.
49
What is it called when certain specialised cells have more than one nucleus? (1)
They are known to be multinucleate.
50
What is the structure of a mitochondria? (2)
-has a double membrane, outer membrane forms a smooth boundary whereas the inner membrane is unfolded to form cristae.
-the interior contains an aqueous solution called the matrix.
51
What is the matrix, in terms of mitochondrion structure? (2)
A solution of metabolites and enzymes, also contain small circular molecules of DNA.
52
What is the function of the mitochondria? (1)
Are the site of aerobic stages of respiration and where most ATP is produced in cells.
53
What is the structure of chloroplasts? (3)
-are biconvex in shape.
-has a double membrane, the outer membrane is a smooth continuous boundary but the inner layer becomes in-touched to form lamellae or thylakoids.
-these membranes are very loosely arranged in an aqueous environment, called the stroma.
54
How are thylakoids arranged, in terms of chloroplast interior structure? (1)
The thylakoids are arranged in flattened circular piles called grana, these look like a stack of coins.
55
What happens at the grana, in terms of chloroplast function? (1)
The chlorophylls and other pigments involved in light capture are located.
56
What is the stroma, in terms of chloroplast structure? (2)
Contains enzymes and often small starch grains, small circular molecules of DNA are also located here.
57
What are plastids? (1)
Organelles that are only found in plant cells and never in animals.
58
What are some examples of plastids? (3)
-chloroplasts
-amyloplasts
-chromoplasts
59
What do amyloplasts do, in terms of plastids? (1)
Where starch is stored.
60
What do chromoplasts do, in terms of plastids? (1)
Contain non-photosynthetic pigments such as carotene (found in root tissue of carrots).
61
What is the function of ribosomes? (1)
Are the site of protein synthesis.
62
How is the size of ribosomes recorded? (1)
Are often recorded in Svedberg units (symbol=S), this is a measure of their rate of sedimentation during centriugation under standardised conditions, rather than their actual size.
63
What is the size of ribosomes in a eukaryotic cell, in terms of Svedberg units? (1)
Ribosomes in the cytoplasm of eukaryotic cells have a sedimentation rate of 80S.
64
In chemical terms, what are ribosomes consisted of? (2)
Are built of two sub-units
-do not have a membrane
-consist of protein and the nucleus acid RNA.
65
Where are ribosomes found? (2)
Free in the cytoplasm or bound to the endoplasmic reticulum to form RER.
66
What is the structure of rough endoplasmic reticulum? (2)
-is continuous and located just outside the nucleus.
-has ribosomes attached to its outer surface.
67
What is the function of the rough endoplasmic reticulum? (2)
-develops the tertiary and quaternary shapes of proteins.
-forms the critical shape of enzymes in its lumen.
68
What is a vesicle? (1)
A small,spherical organelle bounded by a single membrane, which is used to store and transport substances around the cell.
69
What is the structure of the smooth endoplasmic reticulum? (2)
-not usually located near the nucleus.
-has no ribosomes attached to it.
70
What is the function of the smooth endoplasmic reticulum? (1)
-synthesises lipids, phospholipids and steroids.
71
What is the function of the Golgi apparatus? (1)
Is responsible for sorting, modifying and packaging the polymers for secretion or for use within the cell.
72
What is the structure of lysosomes? (2)
Are small spherical vesicles bound by a single membrane.
-contain a concentrated mixture of hydrolytic enzymes, produced by the RER and modified by the GA.
73
What is the function of lysosomes? (3)
-involved in the breakdown of imported food vacuoles,old organelles and harmful bacteria that has invaded the body.
74
What is the function of centrioles? (1)
Are involved in moving organelles around in the cytoplasm, and involved in cell division.
75
What is the structure of the cell wall? (
-composed of long, straight fibres of cellulose held together by hydrogen Bonds.
-able to resist stretching, thus prevents the cell bursting.
-contain gaps within its wall, the apoplast pathway.
76
What is the structure of the permanent vacuole? (1)
-takes up the majority of the cell.
-surrounded by a specialised membrane called the tonoplast.
77
What is the tonoplast? (1)
This is the barrier between the fluid contents of the vacuole and the cytoplasm.
78
What is a nucleoid, in terms of prokaryotic cell structure? (1)
Genetic material, a single circular strand of about 4000 genes.
79
What is the structure of the average prokaryotic cell? (9)
-contains a plasma membrane
-flagella
-cytoplasm
-70S ribosomes
-nucleoid
-cell wall
-plasmids
-Pili
-mesosome
80
What is a plasmid? (2)
Small, circular DNA molecules in their cytoplasm, contain only a few genes.
Often include genes conferring resistance to specific antibiotics.
81
What is the function of the flagella? (1)
Brings about movement of the bacterium.
82
What is the function of the pili? (1)
Enable attachment to surfaces and to other bacteria.
83
What is the cell wall made out of, in terms of prokaryotic cells? (1)
They are made out of peptidoglycan.
84
What is meant by gram positive, in terms of bacteriology? (1)
When bacteria have thick walls made almost entirely of peptidoglycan.
85
What is meant by gram negative, in terms of bacteriology? (1)
When bacteria has thin walls of peptidoglycan with an additional outer membrane.
86
How do gram positive bacteria react to specific antibiotics, in terms of bacteriology? (1)
Gram positive bacteria are susceptible to penicillin.
87
How to gram negative bacteria react to specific antibiotics, in terms of bacteriology? (1)
The other lipid-rich, membrane of gram negative bacteria is relatively impermeable to antibiotics, thus gram negative bacteria are resistant to many types of antibiotic, including penicillin.
88
What are DNA viruses? (1)
Contain DNA, acts as a template for the manufacture of new DNA and mRNA to make viral proteins.
89
What are some examples of DNA viruses? (2)
Bacteriophage which are viruses that infect bacteria such as lambda bacteriophage.
90
What are RNA viruses? (1)
Contain RNA, makes new RNA from it, contain no DNA.
91
What is an example of an RNA virus? (1)
TMV- tobacco mosaic virus.
92
What is a retro virus? (1)
Type of RNA virus, contain RNA that directs the synthesis of the enzyme reverse transcribe
93
What is an example of a retrovirus? (1)
HIV- human immunodeficiency virus
94
What is the Lytic cycle? (1)
In which the viral genetic material replicates independently of host DNA. New viruses are released by lysis.
95
What is the lysogenic cycle? (
In which the viral nucleus acid is incorporated into the host cells genetic material and spread though host-cell reproduction. The viral nucleus acid remains inactive for years before it starts to replicate.
96
What is meant by latent, in terms of the lysogenic cycle? (1)
When a viral nucleus acid remains inactive in a host cell.
97
Hat is meant by non-virulent, in terms of he lysogenic cycle?(1)
When a viral nucleus acid remains latent for a long period of time inside a host cell.
98
What can trigger a non-virulent viral nucleic acid to become active? (1)
If a host cell receives damage it can trigger the viral nucleic acid to become active, then it participates in the lytic cycle.
99
How do retroviruses replicate? (2)
A retro viruses area special case to the lysogenic cycle, the RNA is translated to the DNA by reverse transcriptase in the host cell. Viruses leave the cell by exocytosis and not lysis.
100
When did Ebola first appear? (2)
In Africa in 1976.
101
What is the death rate for Ebola? (1)
50-90% is the death rate.
102
When do symptoms of Ebola occur? (1)
1-2 weeks after symptoms begin.
103
When did the second out break of Ebola begin? (1)
In 2014, in 2015 the death rate surpassed 10,000.
104
What are the preventions to stop the spread of Ebola? (6)
-affected areas should be isolated
-protective equipment should be worn
-car should be taken handling blood and other bodily fluids
-medical equipment sterilised and disposed carefully
-any waste including bodies of the dead should be disposed of carefully
105
In terms of drug development, how long did phase 1 last for the Ebola trial? (1)
1.5 years, a small number of participants to assess safety.
106
In terms of drug development, how long was phase 2 for the Ebola trail? (1)
2 years, over 100 participants to study efficiency.
107
In terms of drug development, what happened before the first phase of any drug trial? (1)
Preclinical research, discovering and early screening of compound, along with animal testing.
108
In terms of drug development, how long was phase 3 of the Ebola trial? (1)
3.5 years, over 1000 participants to study safety, efficiency and dosage.
109
In terms of drug development, how long is the review period for the Ebola trial? (1)
1.5 years.
110
What is cell theory? (1)
The unifying concept that states that cells are a fundamental unit of structure function and organisation in all living organisms.
111
What is contained within the nucleolus? (2)
DNA, RNA and proteins.
