MCB 300 EXAM 2 QUESTIONS WITH VERIFIED
ANSWERS
What is panspermia? - answers - one theory on the origin of life. This stated that life
was shuttled to earth on comets and/or asteroids.
What are the two theories on the origin of life? - answers - 1: that life was shuttled to
earth on comets and/or asteroids known as panspermia
2: life started in the bottom of the ocean near the hydrothermal vents
Where do people think life started on earth - answers - at the bottom of the ocean near
the hydrothermal vents
Describe the miller-urey experiment - answers - they wanted to see if inorganic
compounds and energy could make life
So what did they do? - answers - used a close flask that had the bottom be the ocean,
and then the atmosphere that contained inorganic materials that mimicked earth's
atmosphere, these included methane (ch₄)
Ammonia (nh₃)
Hydrogen (h₂)
Water vapor (h₂o)
What did the condensor and electrodes do? - answers - condensor condensed the
gases into liquid and circulated back into the system like rain and the electrodes
provided the energy
After six days what did they find - answers - over six days, many organic molecules
including several amino acids including glycine, alanine and b-alanine. Also,
Detected acetic acid, formic acid , butyric acid.
Conclusion: early atmosphere, including its chemical constituents, and high energy
electricity provided conditions for
Life to emerge.
Inorganic materials + energy = organic materials
What is the definition of metabolism - answers - the series of biochemical reactions
needed to sustain life
What do all microorganisms rely on - answers - common set of requirements
-water, source of energy to do work, source of electrons to perform biochemical
reactions, and nutrients to build macromolecules
First law of thermodynamics - answers - energy is neither created no destroyed
,Is exergonic catabolic or anabolic - answers - catabolic as making bonds release energy
in this case atp is generated
What about endergonic - answers - this is precursors to cellular materials and is
anabolic reactions where atp is consumed to synthesize biomolecules
What is a reducing power? - answers - the ability of a chemical species to donate
electrons to another molecule
What is a redox reaction - answers - transfer of electrons between substances
Is reduced mean they have electrons - answers - yes oftentimes electron donors go
from reduced to oxidized
What are the three things that all cells require - answers - nutrients, free energy, and
reducing power (ability for a cell to donate electrons
When you are reduced what does that mean? - answers - this means you gain electrons
from h
How many electrons does a h have? - answers - 2 electrons
What are the two energy storage compounds - answers - glucose and lipids
What does glucose serve as - answers - a carbon source and a reducing power as the
carbon is moderately reduced and rich source of electrons
Why is glucose good for storage - answers - because it is easily polymerized
Is glucose soluble? - answers - yes and it is very compatible with aqueous cytoplasm
What does glucose feed directly into? - answers - glycolysis
What is the net energy for glucose versus lipids? - answers - glucose is 4/g and lipids
are 9/g
What is a triglyceride composed of? - answers - 3 fatty acids and glycerol
Highly reduced carbon chains as there are many c-h bonds
Is it hydrophobic? - answers - yes but it does have a long term energy reserve
What is the formula for glucose? - answers - c6h12o6
Difference between triglycerides and lipids - answers - when discussing lipids, we are
talking about membranes not energy storage
, Why do we not use fatty acids for our energy as opposed to glucose? - answers -
because glucose is much smaller and a lot more compatible
What is the cell's immediate energy currency? - answers - atp
What does atp couple? - answers - exergonic to endergonic reactions
Can atp be recycled? - answers - yes it can be recycled rapidly
What are the three parts of atp - answers - triphosphate then ribose then adenine
How is the energy stored in atp - answers - in the bonds between the phosphate groups
(there are three)
What is a proton motive force? - answers - this is the electrochemical gradient of
protons across a membrane that stores energy
What does a pmf do? - answers - drives atp synthesis and powers transport and motility
in things such as flagella
Describe how this works? - answers - protons move from negative outside to positive
inside making atp, travel down their proton gradient
What else can pmf power? - answers - active transport of molecules like glucose import
or nutrient uptake
What are the four trophic classifications based on? - answers - energy acquisition
strategies
What are the two dividing factors of trophs? - answers - the energy source (light or
chemicals) or the carbon source
What are phototrophs versus chemotrophs? - answers - phototrophs is light
Chemotrophs is chemicals
What about carbon source - answers - this is how biomass is built
Autotrophs use inorganic compounds like co2, nitrate, ammonia
Heterotrophs use organic compounds and derive from other organisms
Chemoheterotrophs - answers - synthesize atp using chemicals but build biomass using
organic compounds
Chemoautotrophs - answers - synthesize atp using chemicals but build biomass using
inorganic compounds
ANSWERS
What is panspermia? - answers - one theory on the origin of life. This stated that life
was shuttled to earth on comets and/or asteroids.
What are the two theories on the origin of life? - answers - 1: that life was shuttled to
earth on comets and/or asteroids known as panspermia
2: life started in the bottom of the ocean near the hydrothermal vents
Where do people think life started on earth - answers - at the bottom of the ocean near
the hydrothermal vents
Describe the miller-urey experiment - answers - they wanted to see if inorganic
compounds and energy could make life
So what did they do? - answers - used a close flask that had the bottom be the ocean,
and then the atmosphere that contained inorganic materials that mimicked earth's
atmosphere, these included methane (ch₄)
Ammonia (nh₃)
Hydrogen (h₂)
Water vapor (h₂o)
What did the condensor and electrodes do? - answers - condensor condensed the
gases into liquid and circulated back into the system like rain and the electrodes
provided the energy
After six days what did they find - answers - over six days, many organic molecules
including several amino acids including glycine, alanine and b-alanine. Also,
Detected acetic acid, formic acid , butyric acid.
Conclusion: early atmosphere, including its chemical constituents, and high energy
electricity provided conditions for
Life to emerge.
Inorganic materials + energy = organic materials
What is the definition of metabolism - answers - the series of biochemical reactions
needed to sustain life
What do all microorganisms rely on - answers - common set of requirements
-water, source of energy to do work, source of electrons to perform biochemical
reactions, and nutrients to build macromolecules
First law of thermodynamics - answers - energy is neither created no destroyed
,Is exergonic catabolic or anabolic - answers - catabolic as making bonds release energy
in this case atp is generated
What about endergonic - answers - this is precursors to cellular materials and is
anabolic reactions where atp is consumed to synthesize biomolecules
What is a reducing power? - answers - the ability of a chemical species to donate
electrons to another molecule
What is a redox reaction - answers - transfer of electrons between substances
Is reduced mean they have electrons - answers - yes oftentimes electron donors go
from reduced to oxidized
What are the three things that all cells require - answers - nutrients, free energy, and
reducing power (ability for a cell to donate electrons
When you are reduced what does that mean? - answers - this means you gain electrons
from h
How many electrons does a h have? - answers - 2 electrons
What are the two energy storage compounds - answers - glucose and lipids
What does glucose serve as - answers - a carbon source and a reducing power as the
carbon is moderately reduced and rich source of electrons
Why is glucose good for storage - answers - because it is easily polymerized
Is glucose soluble? - answers - yes and it is very compatible with aqueous cytoplasm
What does glucose feed directly into? - answers - glycolysis
What is the net energy for glucose versus lipids? - answers - glucose is 4/g and lipids
are 9/g
What is a triglyceride composed of? - answers - 3 fatty acids and glycerol
Highly reduced carbon chains as there are many c-h bonds
Is it hydrophobic? - answers - yes but it does have a long term energy reserve
What is the formula for glucose? - answers - c6h12o6
Difference between triglycerides and lipids - answers - when discussing lipids, we are
talking about membranes not energy storage
, Why do we not use fatty acids for our energy as opposed to glucose? - answers -
because glucose is much smaller and a lot more compatible
What is the cell's immediate energy currency? - answers - atp
What does atp couple? - answers - exergonic to endergonic reactions
Can atp be recycled? - answers - yes it can be recycled rapidly
What are the three parts of atp - answers - triphosphate then ribose then adenine
How is the energy stored in atp - answers - in the bonds between the phosphate groups
(there are three)
What is a proton motive force? - answers - this is the electrochemical gradient of
protons across a membrane that stores energy
What does a pmf do? - answers - drives atp synthesis and powers transport and motility
in things such as flagella
Describe how this works? - answers - protons move from negative outside to positive
inside making atp, travel down their proton gradient
What else can pmf power? - answers - active transport of molecules like glucose import
or nutrient uptake
What are the four trophic classifications based on? - answers - energy acquisition
strategies
What are the two dividing factors of trophs? - answers - the energy source (light or
chemicals) or the carbon source
What are phototrophs versus chemotrophs? - answers - phototrophs is light
Chemotrophs is chemicals
What about carbon source - answers - this is how biomass is built
Autotrophs use inorganic compounds like co2, nitrate, ammonia
Heterotrophs use organic compounds and derive from other organisms
Chemoheterotrophs - answers - synthesize atp using chemicals but build biomass using
organic compounds
Chemoautotrophs - answers - synthesize atp using chemicals but build biomass using
inorganic compounds
