Module 1 ^O^ Flashcards

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1
Q

What makes something alive?

A
Movement
Respiration
Sensitivity
Growth
Reproduction
Excretion
Nutrition
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2
Q

Compare prokaryotes and eukaryotes

A

Prokaryotes: simplest and most ancient type of cell - means ‘before nucleus’ (i.e. organelles not enclosed in a membrane)
Eukaryotes: evolved from prokaryotic cells - ‘true nucleus’ (i.e. enclosed in membrane)

Prokaryotes: 0.1-5.0um in size
Eukaryotes: 10-100 um

Prokaryotes: form single celled organisms such as archae bacteria and eubacteria

Eukaryotes: forms multicellular and unicellular organisms such as protsists, fungi, plants, animals

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3
Q

History of prokaryotes and eukaryotes

A
  • 3000mya meteorites that landed in the ocean released minerals and amino acids, causing single celled bacteria to form
  • 2000 - 1500 mya: more complex life (eukaryotes) developed –> Theory is that prokaryotic cell engulfed another prokaryotes and the bacteria took on the role of producing energy for the host cell
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4
Q

Magnification definition

A

The degree to which a lens can make an object appear larger

magnification = image size / actual size

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5
Q

Resolution definition

A

The ability to see two objects as separate from one anotehr

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6
Q

Field of view definition

A

What you can see in the microscope

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7
Q

To calculate cell width:

A

diameter of field of view / number of cells that fit across it

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8
Q

Compare light microscopes to electron microscopes

A

Magnification:
L - light pass through the biconvex lens and is refracted toward eye (1500x)
E - a beam of electrons creates an image of the specimen (1 000 000x)

Resolution:
L - up to 0.2 micrometres
E - up to 0.0002 micrometres

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9
Q

Advantages and Disadvantages of the light microscope and electron microscope

A

Light Microscope
Advantages = able to observe living things, is portable and affordable, efficient preparation of samples, coloured stains can be used for contrast
Disadvantages = limited magnification, poor resolution

Electron microscope:
Advantages - resolution and magnification increase
Disadvantages - expensive to use, preparation takes longer, uses a vacuum which kills living organisms

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10
Q

TEM vs SEM

A

Transmission electron microscope:
Electrons transmitted through specimen
Image produced in 2D

Scanning Electron Microscope:
Bombards with a beam of electrons, causing emissions of secondary surface electrons.
Image produced in 3D

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11
Q

Cell Theory: initial theory

A

Proposed by Aristotle: spontaneous generation i.e. life arises from non-living matter

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12
Q

Cell Theory Points

A
  1. All living things are made of cells
  2. Cells are the smallest part of life
  3. All living things arise from pre-existing cells
  4. Cells contain hereditary information which is passed on during cell division
  5. Cells have the same basic chemical composition
  6. All energy flow (resulting form chemical reaction) of life occurs within cells
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13
Q

Technological Advances that formed the Cell Theory points: “All living things are made of cells”

A

Schleiden and Schwann discovered plant and animal tissues all had the same structural build i.e. cells

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14
Q

Technological Advances that formed the Cell Theory points: Cells are the smallest part of life

A

Hooke observed cork using a very simple microscope and discovered ‘cells’. Leeuwenhoek used an improved microscope (300x) and discovered cells as living things (animalcules)

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15
Q

Technological Advances that formed the Cell Theory points: All living things arise from pre-existing cells

A

Spontaneous generation theory refuted by Virchow who discovered that cells ‘divided’ to reproduce - exposing broth to air experiment

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16
Q

Technological Advances that formed the Cell Theory points: Points 4, 5, 6

A

Invention of electron microscope allowed for a higher magnification and resolution and resulted in a better understanding of the structures and processes of cells.

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17
Q

Animal Cell Structures

A
Nucleus 
Endoplasmic reticulum 
Lysosomes
Golgi bodies
Mitochondria
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18
Q

Plant cell structures

A

Cell Wall

Chloroplast

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19
Q

Nucleus

A

Function = control and information centre

  • stores DNA needed to control cell activities through proteins
  • double nuclear membrane with pores
  • a copy of DNA called MRNA is posted out of the pores to the building location
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20
Q

Endoplasmic Reticulum

A

Transport

  • Rough ER: transport of proteins (network of flattened interconnected membranes that make up pathways) covered in ribosomes
  • smooth ER: produces lipids used for membrane repair
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21
Q

Lysosomes

A

Small fluid filled sacs which act like cellular incinerators - single membrane and filled with digestive enzymes
- break down worn out cell organelles - membrane prevents the lysosome from digesting the rest of the cell

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22
Q

Golgi bodies

A

Process, packaging and sorting:

  • proteins arrive from the RER and are processed (i.e. addition of a protein or carbohydrate)
  • packaged into vesicles
23
Q

Mitochondria

A

Energy production

  • location of cellular respiration
  • double membrane (outer gives shape, inner folded into cristae)
24
Q

Cell wall

A

Rigid, semi permeable protective layer surrounding membrane that provides strength and support.
Matrix of cellulose fibres (turgidity) can be surrounded by lignin

25
Q

Chloroplast

A

belongs to ‘plastids’ (double membrane cells responsible for photosynthesis)
- stacks of thylakoids called grana

26
Q

Fluid mosaic model parts

A

Phospholipids with a hydrophilic head and hydrophobic tail

Receptor proteins
Channel proteins 
Peripheral proteins 
Glycoproteins 
Cholesterol
27
Q

Trans-membrane proteins

A

Produce channels that allow some materials to cross through the membrane.

28
Q

Receptor proteins:

A

Cause cells to response only to certain signals from substances such as hormones that bind to them (specialised)

29
Q

Glycol-proteins

A

Made up of a protein with a carbohydrate molecule attached - proteins identify the cells and are called antigens

30
Q

Cholesterol

A

maintains the membrane’s stability and fluidity at various temperatures by interacting w fatty acid tails to moderate the properties of the membrane

31
Q

Peripheral proteins

A

Do not cross the membrane and act as partners for other proteins

32
Q

Simple Diffusion

A

Passive transport
Non-polar, small, lipid soluble particles
Example: oxygen and carbon dioxide

33
Q

Facilitated diffusion

A

passive transport
large, polar molecules
Carrier molecules are needed (such as channel proteins)
Example: ions, salts

34
Q

Active transport (low to high concentration)

A

Active transport
Large, polar molecules
Carrier molecules required
Example: glucose, protein

35
Q

Osmosis

A

Passive transport
Movement of water molecules only
Through aqua pores

36
Q

Endocytosis

A

Active transport moving large molecules and parts of cells into a cell. Plasma membrane invaginates, forming a pocket across the target molecule and contains it in a vesicle.

37
Q

Exocytosis

A
Expels materials (such as waste, neurotransmitters, proteins) from the cell 
Waste is enveloped in a membrane and fuses with the interior of the plasma membrane.
38
Q

Cell requirements

A

Energy: as light energy (photosynthesis) or as chemical energy (through absorption of food)

39
Q

Organic chemicals:

A

Carbon, hydrogen, oxygen and nitrogen (key components of proteins, carbohydrates, lipids, nucleic acids)

40
Q

Carbohydrates as an organic chemical

A

Sugar, starch, cellulose, glycogen:

  • made up of oxygen and carbon and hydrogen
  • monomer structure = glucose (sucrose is the disaccharide)
  • polymer structure = carbohydrate
41
Q

Protein as an organic chemical

A

Oxygen, carbon, hydrogen, nitrogen

  • amino acids
  • polypeptide
42
Q

Lipids as an organic chemical

A

Oxygen, carbon and hydrogen

  • fatty acid
  • lipid structure
43
Q

Nucleic acid

A

Carbon, hydrogen, nitrogen, phosphorus, oxygen

  • nucleotide
  • Deoxyribonucleic acid
44
Q

Photosynthesis

A

CO2 + H2O –light–> C6H12O6 + O2 + H2O

  • chloroplast is the site of photosynthesis
  • 2 stages of photosynthesis
45
Q

Photosynthesis: Light Dependent Reaction

A

The light hits the chlorophyll and 6 oxygen atoms split away form 12 water molecules, leaving 24 hydrogen.
Hydrogen atoms are carried into the light independent reactions on NADP. 18ATP molecules are formed.

46
Q

Photosynthesis: light independent reactions

A

12 molecules of NADPH2 is combined with CO2 to produce glucose and left over water molecules

47
Q

Cellular respiration

A

Site = mitochondria
3 stages:
- glycolysis: splits the glucose molecule into smaller molecules, produced ATP and NADH
- Krebs cycle: waste product of CO2, left with hydrogen in original glucose held in the molecules NADH
- electron transport chain: hydrogen gets passed along the membrane, giving off ATP, production of water

48
Q

Cellular waste removal

A

Carbon dioxide - cellular respiration
Urea - digestion of proteins
Lactic acid - anaerobic respiration
Hydrogen peroxide - many metabolic processes
Ethanol - fermentation in yeast and plants
Hydrogen sulfide - anaerobic cellular respiration

49
Q

Enzyme parts

A

Substrate (what the enzyme acts on), product

Active site

50
Q

Lock and Key Model

A

Suggests the geometric shape of a substrate exactly fits the active stie of the enzyme
Doesn’t explain why the substrate would be changed in the process

51
Q

Induced fit model

A

Suggests that the shapes of the substrate are close but not an exact fit

52
Q

Effect of environment on enzymes

A

Temperature, pH

  • coenzyme: enables substrate to fit the active site better (but after this happens the coenzyme needs to be replaced)
  • cofactor: an inorganic molecule that acts as an enzyme
  • enzyme inhibitor: fits into the active site and makes the enzyme fit worse
53
Q

Concentration of the substrate

A

Enzymes becomes saturated with substrate, adding more substrate will not increase the rate of reaction

54
Q

Concentration of the enzyme

A

As the concentration of the enzyme increases, so will the rate of reaction, assuming the concentration of substrate is constant