Exam 1 Import Flashcards

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1
Q

What do membranes do? (5)

A
  • define life forms as distinct entities,
  • separates cell from outside world,
  • necessary to perform internal chem. rxns,
  • maintain diff. environment w/i eukaryotic cell,
  • important role in formation of life/evolution
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2
Q

Membrane composition

A

-Lipids and proteins
Phospholipids arranged as lipid bilayer
Proteins can span across both layers or may be attached to 1
Proteins and lipids modified w/ carbs

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3
Q

What are Phospholipids?

A

a lipid consisting of a glycerol bound to two fatty acids and a phosphate group

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4
Q

Define amphipathic.

A

having both a hydrophilic region and a hydrophobic region; can spontaneously form a bilayer in H2O

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5
Q

What is Fluidity?

A

behave like crystals (liquid) b/c they form ordered arrays (proteins also fluid); controlled by degree fatty acid saturation (not too fluid or too rigid)

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6
Q

What is Fluidity Regulation?

A

Animal cells insert cholesterol in between lipid bilayer
Low temp = cholesterol acts as spacer (Increase fluidity)
High temp = cholesterol prevents weakening of membrane (hydrophilic heads together)
Plants use other sterols

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7
Q

Compartmentalization

A

Membrane-bound organelles allow different parts of the cell to perform different functions at the same time (ORGANELLES)

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8
Q

Concentration Gradients

A

results from an unequal distribution of ions inside and outside of the the cell

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9
Q

electrochemical gradient

A

The diffusion gradient of an ion, which is affected by both the concentration difference of an ion across a membrane (a chemical force) and the ion’s tendency to move relative to the membrane potential (an electrical force).

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10
Q

voltage gated channels

A

Electrical charge caused by an imbalance in ions; open and close in response to changes in membrane potential

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11
Q

ligand-gated channels

A

respond to chemical messengers

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12
Q

Vesicles

A

small membrane sacs that specialize in moving products into, out of, and within a cell

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13
Q

selective permeability

A

Keep inside in and outside out
Must allow nutrients and molecules in
Must allow waster and molec out
Entrance=size and charge of particle (also comp of membrane)
Biological membrane: some things in but not others

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14
Q

Transport proteins

A

A transmembrane protein that helps a certain substance or class of closely related substances to cross the membrane.

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15
Q

Diffusion

A

Particles move high to low
Equilibrium reached when equal
Particles can still move back and forth but no net change

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16
Q

Osmosis

A

Diffusion of H2O across membrane
H2O=high to low
Dissolved solute lowers H2O by interacting with H2O molec and preventing movement across
H2O moves toward area of high solute

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17
Q

Facilitated Diffusion

A

Particle binds to protein in membrane
Binding causes protein to change shape and allow cell in
Enter cell following concentration gradient
Ex: Glucose uniporter in red blood cells

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18
Q

Vasoconstriction

A

nervous system restricts blood flow to fingers and toes (grip)

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19
Q

isotonic

A

equal (.9% NaCl)

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20
Q

hypotonic

A

less inside than outside (0.4% NaCl) less H2O inside

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21
Q

hypertonic

A

more H2O inside (1.3% NaCl)

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22
Q

Active transport

A

move particles against the concentration gradient (energy required)

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23
Q

uniporter, symporter, antiporter

A

carries one solute
carries two solutes in same direction
carries two solutes in opposite direction

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24
Q

secondary active transport

A

Form of active transport which does not use ATP as an energy source; rather, transport is coupled to ion diffusion down a concentration gradient established by primary active transport.

25
Q

Exocytosis

A

cargo=stored in vesicles in cell
-waste products
-hormones
reside fuses w/ cell membrane releasing cargo outside cell

26
Q

Endocytosis

A

A process in which a cell engulfs extracellular material through an inward folding of its plasma membrane.

27
Q

receptor-mediated endocytosis

A

capture specific macromolecules from cells environment) method which cholesterol is taken up by most mammalian cells

28
Q

Coated pits

A

indentations in the plasma membrane and their cytoplasmic surfaces are covered in other proteins (ex: clathrin)

29
Q

of calories per gram of fat

A

9

30
Q

Energy

A

the capacity to do work

31
Q

Work

A

change in state/motion of matter

32
Q

1 kcal= ? kJ

A

4.184 kJ

33
Q

Potential Energy (PE)

A

stored energy

34
Q

kinetic energy

A

energy of motion

35
Q

Living organisms convert

A

kinetic into potential which can be stored/used to create kinetic

36
Q

Laws of Thermodynamics

A

1) energy can not be created or destroyed, only converted from one form to another
2) disorder increases in the universe

37
Q

Entropy

A

measure of disorder in the universe

38
Q

Gibbs Free Energy

A

The total amount of energy available in a system to do work.

total energy=free energy =entropy or H=G+ST

39
Q

Endergonic

A

(+G) requires energy; net input of energy is required and products have more energy than reactants

40
Q

Exergonic

A

(-G) releases energy; spontaneous

41
Q

G=0

A

reaction is at equilibrium

42
Q

Coupling Reactions

A

Energy released from one reaction can be used to drive another reaction
Engergonic rxns (protein synthesis, phosynthesis, etc.) need energy so couple them to exergonic
A to B (+5 kcal energy)
C to D (-8 kcal energy)
A+C to B+D (-3 kcal energy)

43
Q

Annabolism

A

formation of complex molec from simpler building blocks

Ex: amino acids to proteins, nucleotides to DNA

44
Q

Catabolism

A

breakdown of larger molecules into smaller ones

Ex: starch to monosaccharides

45
Q

ATP

A

(exergonic rxns break down) adenosine triphosphate; energy currency of the cell

  • can be spent to drive rxns
  • saved in chemical bonds of fats/carbs
  • energy freed by breaking bonds between phosphate groups
46
Q

What is glycolysis?

A

first step in releasing the energy of glucose, in which a molecule of glucose is broken into two molecules of pyruvic acid (2e-)

47
Q

What is the citric acid cycle?

A

A chemical cycle involving eight steps that completes the metabolic breakdown of glucose molecules to carbon dioxide; occurs within the mitochondrion; the second major stage in cellular respiration.

48
Q

What is Aerobic Respiration? What are its steps? (4)

A

-Respiration using O2

  • glycolysis
  • formation of acetyl COA
  • tricarboxylic acid cyle (citric acid cycle)
  • 32 ATP e- tranport chain
49
Q

What is ATP synthase?

A

Large protein that uses energy from H+ ions to bind ADP and a phosphate group together to produce ATP

50
Q

What is anaerobic respiration?

A

-Respiration that does not require oxygen; uses chemical other than O as final e- acceptor (e.g. N, S)
less ATP than O2

51
Q

What is Fermentation?

A

-A catabolic process that makes a limited amount of ATP from glucose (2 ATP per glucose) without an electron transport chain and that produces a characteristic end product, such as ethyl alcohol or lactic acid.

52
Q

What is feedback?

A

-The process by which the product of a metabolic pathway influences its own production by controlling the amount and/or activity of one or more enzymes involved in the pathway

53
Q

What is the purpose of photosynthesis?

A

-take energy light and water and make glucose and oxygen

54
Q

What is an Autotroph?

A

-an organism that is able to form nutritional organic substances from simple inorganic substances such as carbon dioxide.

55
Q

What is a Heterotroph?

A

-an organism deriving its nutritional requirements from complex organic substances.

56
Q

Define photosynthesis

A

-plants convert the energy of sunlight into chemical energy stored in the bonds of carbohydrates

57
Q

What is the Calvin Cycle?
Give the steps of it. (4)
Does it repeat?

A

-light-independent reactions of photosynthesis in which energy from ATP and NADPH is used to build high-energy compounds such as sugar

  • CO2 and H2O react w/ RuBP to form 2 molec of phosphoglycerate
  • ATP and NADPH (from light rxn) is spent to convert PGA to G3P
  • 2 G3P are removed from cycle to form sugars
  • remaining G3P used to make more RuBP

-yes

58
Q

What are 3 differences in C3 and C4 plants?

A
  • In C3 plants, the carbon dioxide fixation takes place only at one place. In C4 plants, the carbon dioxide fixation takes places twice (one in mesophyll cells, second in bundle sheath cells).
  • C4: uses CO2 at low concentrations, occurs prior to C3, -CO2 up to 60% greater in C4 plants