module 1 cells as the basis of life Flashcards
(130 cards)
1
Q
Define prokaryotic
A
relating to cells with no membrane bound nuclei or membrane bound organelles
2
Q
Define eukaryotic
A
relating to a cell containing a membrane bound nucleus and membrane bound organelle
3
Q
Define cell membrane
A
a structure that surrounds and encloses a cell
4
Q
Define cell wall
A
the rigid outer layer of a cell that gives the cell support and structure
5
Q
Define capsule
A
the outer layer of a bacterial cell, composed of of complex carbohydrates
6
Q
Define cytoplasm
A
the fluid part of the cell outside the nucleus
7
Q
Define archaea
A
one of the two domain of prokaryotes, often living in extreme environments. They are structurally similar to bacteria
8
Q
Define flagella
A
A whip like tail that provides a cell with locomotion
9
Q
Define nucleus
A
the membrane bound structure in a cell that contains the genetic material of an organism
10
Q
Define organelle
A
an internal structure or part of the cell that is enclosed by a membrane and has a particular function
11
Q
Define plasmid
A
the circular ring of genetic material in a prokaryotic cell
12
Q
Define Ribosomes
A
a very small, spherical structure found in the cytoplasm that contains both RNA and proteins, its function is to manufacture proteins required by the cell
13
Q
Define Unicellular
A
made up of a single cell
14
Q
Define pili
A
hair like structures on the surface of a cell
15
Q
What is cell theory?
A
All living things are made up of one or more cells or products of cells. The cell is the simplest unit of life. Cells are produced by existing cells.
16
Q
structure of cell membrane
A
Composed of protein and lipid molecules, often referred to as a bi-lipid layer
- Hydrophilic heads towards cytoplasm, and hydrophobic tails inwards - this makes it fluid
- Proteins allow materials to move through and create pores, some carry substances through
17
Q
function of cell membrane
A
- acts as a boundary layer to contain the cytoplasm
- interlocking surfaces bind cells together
- selectively permeable to select chemicals that pass in and out of cells
18
Q
cell wall structure
A
- provides strength and support
- some are thickened with additional chemicals
19
Q
cell wall function
A
- shape and support
20
Q
vacuole structure
A
- large permanent, fluid
- filled sacs in the cytoplasm of mature plant cell
- consists of a water solution called cell sap
- surrounded by single membrane
21
Q
vacuole function
A
- Storage function
- cytoplasm, provides support → fills up with water pushing outwards cell becomes rigid
22
Q
nucleus structure
A
- consists of the nuclear envelope, nucleolus, chromatin and nucleoplasm
23
Q
nucleus function
A
- the repository of genetic information and as the cell’s control center
24
Q
nucleus envelope structure
A
- consists of 2 nuclear membranes
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nucleus envelope function
- barriers between the nuclear contents
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chromatin structure
- made up of protein and nucleic acid
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chromatin function
- to package DNA into a unit capable of fighting within the nucleus
28
nucleolus structure
- dark staining body in the nucleus
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nucleolus function
- site of synthesis of ribosomal RNA (that makes up ribosomes)
30
chloroplast structure
- organelles found only in plant cells that contain green pigment chlorophyll
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chloroplast function
- they carry out the process of photosynthesis
- this process requires carbon dioxide, water and sunlight to produce energy (mainly sugars) for the cell
32
centriole structure
- dense granular structure
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centriole function
- spindle production in cell division
34
endoplasmic reticulum structure
- a network of flattened membranes
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endoplasmic reticulum function
- used for the transport of protein
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Rough ER structure
ribosomes attached to the surfaces giving it a rough appearance
37
Rough ER function
folds and processes proteins
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Smooth ER structure
no ribosomes present
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Smooth ER function
synthesises lipids for membranes
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ribosomes structure
Found free in cytoplasm or attached to rough ER
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ribosomes function
Responsible for protein synthesis necessary for the cell to function
42
golgi apparatus structure
- a network of membranes that are curved and stacked in groups of 4-10
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golgi apparatus function
- the function is to process, package and sort cell products
- vesicles can be seen budding off as proteins and continue on their final destination which can be located inside or outside the cell
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mitochondria structure
- double membrane system
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mitochondria function
- site of cellular respiration
- responsible for producing ATP, an energy molecule so the cell can be carried out
46
lysosome structure
- sacs filled with digestive enzymes
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lysosome function
- they break down worn out cell organelle so that the new materials can be recycled to make new organelle
48
what organelle do animal cells have that plant cells do not
- centriole
- lysosomes
49
what organelle do plant cells have that animal cells do not
- cell wall
- vacuole
- chloroplast
50
what organelle do plant and animal cells share
* cell membrane
* nucleus
* cytoplasm
* ribosomes
* mitochondria
51
features of a eukaryotic cell
* Size 10-100 um
* contains lysosomes
* multicellular + unicellular
* membrane bound nucleus with DNA material
* membrane bound organelle
* multiple linear chromosomes
* reproduce with mitosis
52
example of a eukaryotic cell
plants, animals, humans
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features of a prokaryotic cell
* Size 0*1-5.0 um
* singular circular chromosome
* cell wall
* pili
* flagella
* capsule
* unicellular only
* reproduce with binary fusion
54
example of prokaryotic cell
bacteria + arched
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features of both eukaryotic and prokaryotic cells
* cytoplasm
* unicellular
* cell membrane
* ribosomes
* DNA
56
magnification and resolution of a light microscope
2000x or 1500x
200nm
57
how an image is produced by a light microscope
Light source passes through the lens onto the specimen and then passes through the convex lens. Image is then magnified through the ocular lens
58
pros and cons of a light microscope
Advantages
Living and non-living species can be viewed
Disadvantages
The limited resolution makes it difficult to see small details
59
magnification and resolution of a fluorescent microscope
100x
180nm
60
how an image is produced by a fluorescent microscope
Specimen is labelled with a fluorescent substance then the light shines through and the fluorescent emits light thus the image is created
61
pros and cons of a fluorescent microscope
PROS: Extra features are able to be seen with high amounts of light shone through it
CONS:Cells become damaged due to interaction between fluorescent dye and excitation light.
62
magnification and resolution of a transmission electron microscope (TEM)
1500000 x
2nm
63
how an image is produced by a transmission electron microscope (TEM)
Electrons transmitted pass through the specimen
64
pros and cons of transmission electron microscope (TEM)
PROS: Detailed 2D image
CONS: Living tissue cannot be used due to the air interference
65
magnification and resolution of a scanning electron microscope (SEM)
100000 x
20nm
66
how an image is produced by a scanning electron microscope (SEM)
The released electrons are in high amounts and thus cause the release of more electrons from specimen
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pros and cons of a scanning electron microscope (SEM)
PROS:In a SEM, electron beams bounce off surfaces and create a three-dimensional image.
CONS: Living tissue cannot be used due to the air interference
68
magnification and resolution to a Confocal laser scanning microscope
150 x
25nm
69
how an image is produced by a Confocal laser scanning microscope
The laser is directed onto a pair of scanning mirrors sweeping the beam in directions of a single field of view and then moved across the entire sample to produce an image of the section
70
pros and cons of a Confocal laser scanning microscope
PROS:Much greater understanding of the cell’s structure
CONS: There are a limited number of excitation wavelengths available with common lasers
71
what is lysis
when an animal cell does osmosis but it lacks a cell wall so it ruptures
72
structure of a hypothesis
"If [independent variable] increases/decreases, then [dependent variable] will increase/decrease."
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independent variable
what you change
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dependant variable
what you measure
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controlled variables
what you keep the same
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tips for method
- Logical, sequential
- Includes sufficient detail so that it could be replicated
- Includes a diagram
- Explains how the independent variable is manipulated for the purpose of the investigation.
- Explicitly describes how the dependent variable is measured.
- Explains how the controlled variables are managed.
77
what to include in discussion
- Identifies trends in the result data
- Includes data in the trend identified - Explains trends in results data using scientific reasoning.
- Discusses reliability of data collected * Discusses validity of data collected
- Identifies improvements/changes to method
- Uses biological terminology
78
what to include in conclusion
States if hypothesis has been supported or not supported by the results data.
- Identifies if the investigation achieved the aim.
- Concluding findings
79
what is needed in an introduction
* Introduce your research question, what is the problem being
investigated? (This is your aim)
* Describe background research – what is already known?
* State what hypothesis you drew from existing knowledge.
* Explain how your study is beneficial for the scientific community (real
life application or significance to science)
80
what is needed in the aim
- Independent and dependent variables
- correct language
- starts with 'to investigate'
81
what is needed in hypothesis
- Independent and dependent variables
- correct language
- Follows 'if...then' and uses specific data
82
what is needed in risk assessment
* Identifies risk
* Identifies why it’s a risk
* Identifies preventative measures
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what is needed in equipment list
- all items needed for experiment
- specific details
84
what is needed in method
* Logical, sequential
* Includes sufficient detail so that it could be replicated
* Includes a diagram
* Explains how the independent variable is manipulated for the purpose of the investigation.
* Explicitly describes how the dependent variable is measured.
* Explains how the controlled variables are managed.
85
what is needed in data table
* Completely ruled table
* Dependent variable and trials across columns
* Independent variable in first column
* Average
* Units in headings only
86
what is needed in a graph
* Labels on axes
* Units with labels
* Appropriate scale on axes
* Points plotted correctly and joined with a smooth line of best fit
* Only averages graphed
87
acronym for discussion
TERVI
88
what is needed in discussion
* Identifies trends in the result data
* Includes data in the trend identified
* Explains trends in results data using scientific reasoning.
* Discusses reliability of data collected
* Discusses validity of data collected
* Identifies improvements/changes to method
* Uses biological terminology
89
what is needed in conclusion
* States if hypothesis has been supported or not supported by the results data.
* Identifies if the investigation achieved the aim.
* Concluding findings
90
optimum temp for mammals
37
91
optimum temp for plants
25
92
what are enzymes
Enzymes are biological catalysts. They help substrates become products by lowering activation energy, which allows reactions to happen faster. They are made of proteins.
93
what is the area where enzymes attach temporarily called
the polypeptide chain is called the active site.
94
what is substrate
the reactant chemicals in which the enzyme temporarily bonds is the substrate. Enzymes are specific for a given substrate because the shape of an enzyme active site matches a substrate.
95
lock and key model
where the enzyme has a rigid/fixed shape that is specific to a substrate
96
induced fit model
more recent modification of lock and key. It proposes that an active site slightly changes its shape to accomodate the substrate perfectly
97
how to identify enzyme from name
usually named from their substrate suffix if ase
98
example of enzyme
lyases: function is catalyse reactions in which double bonds are added or removed
99
what is an enzyme inhibitor
enzyme inhibitors attach themselves to the enzyme and block its functioning.
100
what is a competitive inhibitor
block the substrate from entering the active site
101
what is a non competitive inhibitors
do not bind at the active site but their presence attached to another part if the enzyme still effects its functioning.
102
describe a graph that shows enzyme activity on substrate concentration
the graph for enzyme activity with substrate concentration shows an initial rapid increase with increeased substrate but the rate levels off at higher levels due to other limiting factors eg amount of enzyme present
103
describe a graph that shows enzyme activity on temperature
The graph shows an enzyme's activity increasing with temperature up to an optimal point, after which activity rapidly declines due to enzyme denaturation.
An enzyme that has partially denatured can regain its shape yet one completely denatured cannot
104
describe a graph that shows enzyme activity on pH
A graph of enzyme activity against pH is typically bell-shaped, peaking at the enzyme’s optimal pH and decreasing at extreme pH levels due to denaturation.
105
why a change in enzyme shape causes it to denature
a change in shape increases movement, therefore temperature increases and more molecules collide, then the enzyme denatures
106
3 ways substances enter the cell
- passive
active
- bulk
107
what is passive transport and eg
the movement of substances into or out of a cell without the expenditure of energy
- MOVING WITH CONCENTRATION GRADIENT
eg: facilitated diffusion and osmosis
108
what is active transport and eg
the movement of substances into or out of a cell requiring the expenditure of energy (in the form at ATP)
eg: proteins called pumps force molecules or ions to move from an area of low concentration to an area of high concentration - MOVING AGAINST CONCENTRATION GRADIENT
109
what is bulk transport and eg
the movement of larger substances into or out of a cell
- vesicles take substance in or out. During this process the plasma membrane surrounds and engulfs the particle which is known as endocytosis
110
what are the 3 main types of endocytosis
- phagocytosis: if the molecule is larger eg bacteria
- pinocytosis: form around liquid or smaller particles
- receptor mediated endocytosis: molecules bind to specific receptor proteins embedded in a coated pit within the plasma membrane; when enough particles accumulate the pit deepens, seals and is incorporated into the cell as a vesicle
111
what is exocytosis
the opposite of endocytosis: membrane bound vesicles move to the surface of the plasma membrane, fuse with the membrane and then release their contents to the outside of the cell
112
what is a hypotonic solution
lower concentration on the outside of the cell of a molecule. Moving inside probability is greater than inside moving out
(net inflow)
113
what is a isotonic solution
even amounts of same concentration of particles inside and out of the cell. Same probability of moving inside and out
(no net flow)
114
what is a hypertonic solution
higher concentration on the outside of the cell of a molecule. Moving out probability is greater than out moving in
(net outflow)
115
what is diffusion
the tendency of all molecules to disperse; the net movement of gas and liquid molecules that move in random directions from high concentration to low concentration with a certain amount of kinetic energy until equilibrium is achieved.
116
what is osmosis
the diffusion of water molecules from areas of high water potential to areas of lower water potential through a partially permeable membrane to achieve equilibrium.
117
turgid v plasmolysed
turgid: water in through osmosis
plasmolysis has occurred through osmosis when water moves out
118
lysis
the breakdown of a cell caused by damage to its plasma (outer) membrane
119
word equation for photosynthesis
Reactants: c02 and water
products: glucose and oxygen
120
word equation for cellular respiration
Reactants: glucose and oxygen
products: c02 and water
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organic compounds
produced by living organisms that have carbon bonds eg lipids
122
inorganic compounds
derived from non living and lack carbon bonds eg water
123
overview of photosynthesis
photosynthesis involves a chain of complex biochemical reactions, which can be generalised into the light reaction (1) and the independent light reaction (2)
- the products of the first reaction become the reactants of the second reaction
124
first reaction in photosynthesis
- requires light hence 'light reaction'
- radiant energy from the sun is absorbed by chlorophyll is converted to chemical energy
- some of this energy is used to split water molecules into hydrogen and oxygen
- occurs on the internal membranes of chloroplasts (thylakoids)
- manganese is needed for release of oxygen
125
second reaction in photosynthesis
uses carbon dioxide and is light independent (carbon fixing stage)
- in this reaction hydrogen from the 1st reaction combines with co2 to form sugar
- requires energy (comes from light absorbed)
- occurs in chloroplasts and stoma
126
what are the products from the 2nd stage of photosynthesis used for
the sugars made are used for cellular respiration
- during the day when light is available for photosynthesis there are more sugars made than used in respiration; stored in starch
- at night this starch is converted back into sugars and used for respiration and plant growth
127
aerobic cellular respiration
the process by which cells obtain energy by breaking down organic molecules eg sugars to produce CO2, water
- related to photosynthesis but not the reverse
- uses oxygen
equation: glucose and oxygen:co2 and water and energy (38ATP)
- efficient in the cytoplasm
128
role of respiration
- to enable organisms within an ecosystem to utilise the energy input from the sun to drive cellular metabolic processes
- eg growth and repair
129
Anaerobic respiration
in the absence of oxygen.
- less energy produced than aerobic
- breaks down glucose to form either lactic acid or ethanol
equation: glucose:co2 and alcohol and energy (2ATP)
- inefficient in the mitochondria
130
2 stages of aerobic respiration
FIRST STAGE
- occurs in cytoplasm
- involves splitting a 6-carbon sugar molecule (glucose) into two 3 carbon molecule (pyruvate) - called GLYCOLYSIS
- 2 molecules of atp are formed during glycolysis
SECOND STAGE
- occurs in mitochondria
- the pyruvate molecules are further broken down into co2
- oxygen is required and combines with hydrogen to form water
- 36 atp molecules are produced
