Cells as the Basis of Life Flashcards

Year 11 Module 1

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1
Q

What is the difference between prokaryotic and eukaryotic cells?

A

Prokaryotes:
* small
* simple structure
* no membrane-bound organelles
* no nuclear membrane
* have plasmids (small accesory chromosomes)
* nucleoid region - circular DNA
* often have a capsule
* often have flagella or pili
* cannot be multicellular

Eukaryotes:
* cellular membrane & cytoplasm
* nucleus containing linear DNA
* membrane-bound organelles and vesicles
* larger
* complex stucture
* can be unicellular or multicellular

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2
Q

What kingdom is prokaryotic?

A

monera (bacteria)

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3
Q

What kingdoms are eukaryotic?

A
  • plants
  • animals
  • fungi
  • protists
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4
Q

Why are plasma membranes fluid?

A

they can move/flow due to phospholipid stucture and lipid bilayer

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5
Q

What is the structure of phospholipids?

A

Hydrophilic phosphate head and hydrophobic fatty acid tail

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6
Q

What is the difference between saturated and unsaturated phospholipids?

A

Unsaturated lipids have a ‘kink’ in the tail and cannot stack neatly together so they are more fluid

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7
Q

What is the function of a plasma membrane?

A
  • keeps cell separate from outside
  • selectively permeable - controls what goes in & out of cell
  • cell-cell and cell-external communication
  • stuctural support
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8
Q

What are some adaptations of plasma membranes?

A
  • strong for support, but flexible to allow growth & movement
  • self-sealing so cell can divide without bursting
  • antigens on surface to recognise other cells
  • receptor sites for hormones & neurotransmitters
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9
Q

What are carrier proteins in the plasma membrane?

A

proteins that bind to specific molecules to transport them across the membrane

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10
Q

What are channel proteins in the plasma membrane?

A

proteins that act as a pore through which molecules can diffuse into the membrane

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11
Q

Which molecules can diffuse through the plasma membrane on their own?

A
  • hydrophobic molecules
  • small uncharged molecules (oxygen and CO2)
  • small polar molecules (water)
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12
Q

Which molecules can diffuse through the membrane via channel proteins?

A
  • charged or large molecules
  • small ions
  • water
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13
Q

Which molecules must be transported across the membrane via carrier proteins?

A
  • sugars
  • amino acids
  • nucleosides
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14
Q

What does cholesterol do in the plasma membrane?

A

regulates fluidity, thickness, water penetration, and structure of lipid bilayer

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15
Q

What do carbohydrate chains do in the plasma membrane?

A
  • cell binding
  • hormone reception
  • nutrient breakdown
  • cell recognition
  • cell communication
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16
Q

What does the mitochondria do?

A

produces cell energy via cell respiration

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17
Q

What do chloroplasts do?

A

contain chlorophyll which convert sunlight energy into glucose by photosynthesis

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18
Q

What does the rough endoplasmic reticulum do?

A
  • covered in ribosomes that produce proteins
  • transports proteins after production
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19
Q

What does the smooth endoplasmic reticulum do?

A
  • depends on type of cell
  • can include producing lipids and hormones
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20
Q

What does the golgi body do?

A

stack of membrane-bound vesicles that package proteins and other molecules for transport

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21
Q

What do lysosomes do?

A
  • contain enzymes to aid digestion
  • produce enzymes involved in immune response
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22
Q

What does the vacuole do?

A
  • store nutrients and waste
  • collect water to provide rigidity in plants
  • larger in plants than animals
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23
Q

What does the ribosome do?

A
  • contains RNA and proteins
  • makes proteins
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24
Q

What is passive transport?

A

the movement of particles without the need for added energy (ATP)

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25
Q

What is diffusion?

A
  • form of passive transport
  • movement of molecules/particles from high conc. to low conc. until equal
  • through a permeable membrane
26
Q

What is facilitated diffusion?

A
  • form of passive transport
  • “assisted” diffusion
  • relies on channel proteins & carrier proteins
  • for charged or large molecules
27
Q

What is osmosis?

A
  • form of passive transport
  • movement of water from high potential (ψ) to low ψ
28
Q

What are the three types of solutions?

A
  • Isotonic - both solutions are the same conc. of dissolved substances
  • Hypotonic - a solution with lower conc. of dissolved substance
  • Hypertonic - a solution with higher conc. of dissolved substance
29
Q

What can affect the rate of diffusion?

A
  • size of particles (smaller = faster)
  • temperature (warmer = faster (more kinetic energy))
  • concenration gradient (higher = faster)
  • state of particles (gas>liquid>solid)
  • distance - thickness of exchange surface (thinner = faster)
  • surface area (larger = faster)
30
Q

What is active transport?

A

uses energy (ATP) to transport molecules against conc. gradient

31
Q

What is endocytosis?

A
  • form of active transport
  • tranport of macromolecules & large particles into the cell
  • part of membrane engulfs particle & folds inward to ‘bud off’
32
Q

What are two types of endocytosis?

A
  • Pinocytosis - liquid
  • Phagocytosis - solid
33
Q

What is exocytosis?

A
  • form of active transport
  • transports wastes and bulk substance out of cell
  • expells waste
  • transports molecules that are too large to pass through membrane
34
Q

What are vesicles?

A

little membrane-bound parcels created by cells to pinch off substances

35
Q

What are vesicles made from?

A

phospholipids and membrane

36
Q

What parts of a cell can make vesicles?

A
  • cell membrane
  • golgi body
  • endoplasmic reticulum
37
Q

What is the role of vesicles?

A

endo & exocytosis

38
Q

How does surface area to volume ratio affect exchange of materials across membranes?

A

higher SA and less volume = faster exchange

39
Q

What is the chemical equation for photosynthesis?

A

6CO₂ + 6H₂O →(sunlight and chlorophyll)→ C₆H₁₂O₆ + 6O₂

Sunlight and chlorophyll would be written above/below the arrow

40
Q

What is the word equation for photosynthesis?

A

Water + Carbon Dioxide →(sunlight and chlorophyll)→ Glucose + Oxygen

Sunlight and chlorophyll would be written above/below the arrow

41
Q

What is the chemical equation for cellular respiration?

A

C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + ATP

42
Q

What is the word equation for cellular respiration?

A

Glucose + Oxygen → Water + Carbon Dioxide + Energy

43
Q

Outline the steps of photosynthesis

A

Photolysis (light-dependant) - Granum
* light splits water into oxygen and H ions
* oxygen diffuses out
* NADPH transports H ions to stroma

Calvin Cycle (light-independant) - Stroma
* Carbon-fixation
* CO₂ and H ions form glucose using ATP
* glucose goes to mitochondria

44
Q

Outline the steps of cellular respiration

A

Glycolysis
* O₂ diffuses into cell
* glucose gets into cell by active transport and facilitated diffusion
* glucose is split into pyruvate

Krebs Cycle
* series of reactions
* CO₂ waste diffuses out of cell into blood
* H ions are carried to ETC by NADH

Electron Transport Chain
* H ions move into cristae
* H ions go through ATP-synthase
* ATP is produced
* H combines with O
* H₂O diffuses out of cell

45
Q

What affects the rate of photosynthesis?

A
  • Light intensity (reaches max point)
  • CO₂ concentration (reaches max point)
  • Temperature (reaches optimal point & then decreases)
46
Q

How do eukaryotic cells remove wastes?

A
  • Exocytosis
  • temporarily transform waste into diff molecule that won’t diffuse back
47
Q

What are 4 ways the body uses ATP?

A
  • synthesis of new molecules
  • mitosis
  • muscle movement
  • thermoregulation
48
Q

Describe the anaerobic respiration in cellular respiration

A
  • oxygen not req.
  • Glycolysis & fermentation
  • occurs in cytoplasm
  • pyruvate isn’t completely oxidised
  • 2 metabolic pathways - alcoholic ferm. or lactic acid ferm.
  • produces 2 ATP per glucose
49
Q

Describe the aerobic respiration involved in cellular respiration

A
  • oxygen req.
  • glycolysis - cytoplasm
  • krebs cycle - mitochondrial matrix
  • electron transport chain - cristae
  • pyruvate is completely oxidised
  • follows one metabolic pathway
  • produces up to 32 ATP per glucose
  • produces CO₂ and H₂O
50
Q

Why would a cell have lots of mitochondria?

A

to produce more ATP for active transport

51
Q

What is this?

A

mitochondrion

52
Q

What are the small dots?

A

ribosomes

53
Q

What are light microscopes?

A
  • use light through series of lenses
  • resolution limited by light wavelength
  • specimens must be thin & mostly transparent
  • can view living tissue/organisms
  • produces coloured images
54
Q

What is the difference between magnification and resolution?

A
  • magnification - number of times larger an object appears
  • resolution - amount of clarity that is possible
55
Q

What are electron microscopes?

A
  • SEM (scanning electron microscope)
  • TEM (transmission electron microscope)
  • use short wavelength of electrons for higher resolution
  • use beam of electrons
  • specimen must be dead/non living
56
Q

Describe a SEM

A
  • scans surface of objects
  • produces 3D images
  • specimen must be in a vacuum and coated with carbon or gold
  • B&W
  • electromagnetic lenses
57
Q

Describe a TEM

A
  • looks through a specimen
  • magnetic lenses
  • achieves highest magnification & resolution
  • specimen must be very thin coated with heavy metal
  • B&W
58
Q

What is an enzyme?

A
  • biological catalyst
  • speeds up reactions without being changed/used up
59
Q

What is the difference between catabolism and anabolism?

A
  • Catabolism - degradation of molecule into smaller units
  • Anabolism - synthesis of smaller units into molecule
60
Q

What does enzyme denaturing mean?

A
  • alteration of active site leading to loss of function
  • breaks bonds in active site changing structure
61
Q

What affects enzyme activity?

A
  • pH level
  • temperature
62
Q

Why do mitochondrion have a highly folded internal structure?

A

to increase surface area and ∴ increase rate of reactions