Transcript Slide 1

1.What organelles/parts do prokaryotes have? Ribosomes,
Flagella, genome(DNA), cell membrane, cell wall, cytoplasm
2. How are prokaryotic and eukaryotic cells different? Size,
Complexity(organelles), nucleus or not, type of cell division
3. Describe the function of each of the following, and if they
can be found in plant, animal, or both.
Cell membrane – phospholipid bilayer with embedded proteins
That determines what enters or exits the cell
Cytoplasm- the oozing watery fluid that fills the cell…it also
Contains much of the building blocks for cellular processes
Nucleus – compartment which contains the master set of DNA
Instructions. The nuclear membrane has pores that allow mRNA
To copy this DNA
Nucleolus- granular region inside the nucleus where parts of
ribosomes are made…in particular, the rRNA
DNA/chromatin- DNA is the code of life expressed in nucleic
Acids of Adenine, Thymine, Guanine, and Cytosine (ACTG) and
Exists as chromatin(pile of spaghetti)most of time.
Rough Endoplasmic Reticulum - part of ER that is freckled with
Ribosomes and deals mostly with protein export
Smooth Endoplasmic Reticulum – ER that does not have
ribosomes and deals mostly with toxin removal and hormone
regulation.
Mitochondria- the endosymbiotic organelle of the cell that is
responsible for cellular respiration that makes ATP. ATP is the
energy source that cells use.
Chloroplasts- (plants only) the endosymbiotic organelle of the
cell that is Responsible for photosynthesis
Ribosomes- the part of the cell where proteins are made
Golgi Apparatus- looks like a series of flattened sacs and is
Responsible for the packaging and transport of cellular products
and byproducts.
Cell Wall- found only in plants and bacteria. This rigid
enclosure consisting of fibrous carbohydrates give structure
and strength to plant cells with the aide of turgor pressure.
Cilia – numerous, short, hair-like structures that provide
coordinated movement to unicellular organisms and move
fluids in multicellular organisms
Flagella- long less numerous hair-like structures that provide
less coordinated movement in cells.
Vacuoles- (plants only)the large central vacuole is only found
in plant cells, and stores water nutrients and waste products.
Cytoskeleton- network of thin fibers(microfilaments) that
provide structure to the eukaryotic cell
Lysosome- (animal only) packet of digestive enzymes
4. Draw a cell membrane. Label hydrophilic phosphate heads,
hydrophobic tails, membrane proteins .
5. Define each, stating whether each takes cellular energy or not,
and whether things are being moved with or against their
concentration gradient:
Diffusion- when a solute disperses through a solvent until it reaches
Equilibrium…this would be like adding a drop of food dye(solute) to
A beaker of water(solvent) and waiting for the dye to distribute
Throughout the water. There is no gradient here nor energy used.
Osmosis – usually this is when water crosses a permeable
Membrane to a higher concentration of solutes(usually salts).
This is like when you take a bath and the water in the tub creeps
Into your cells. Remember osmosis can occur in the other
Direction if you were soaking an injured ankle in epsom salts. Flows
With concentration gradient with no energy used.
Facilitated diffusion -when a cell’s membrane protein escorts
Certain molecules into or out of the cell…the important thing is that
NO NET ENERGY is required for this to happen and it flows with
The concentration gradient.
Active transport – when the membrane proteins USE ENERGY
To force molecules against the concentration gradient(natural
Tendency to flow) This would be like when the proton pumps on
a thylakoid force H+ protons into the thylakoid.
Concentration Gradients exist where a membrane divides two
solutions. Without energy input, there is a natural flow toward
equilibrium that the solutions will make that is based on the
concentrations of solutes in the solvent. To create a gradient it is
necessary for the membrane between areas to be semipermeable(let the solvent pass through, but NOT the solute) for
more understanding on this topic, look at the isotonic,
hypertonic, hypotonic relationships of question # 6
Endocytosis – when a cell wraps itself around an external particle
and engulfs it into the cell.
Exocytosis – when a cell releases a vesicle(internal packet) into
its surrounding environment
Concentration Gradients aren’t really a direct factor to consider
In endocytosis or exocytosis.
6. Draw pictures of isotonic, hypertonic and hypotonic.
For each
Of these situations you must consider two environments that are
Encountering each other. Of the two, the hypertonic solution will be the one
With more stuff(solute) dissolved in it and the hypotonic solution will be the one
With less stuff(solute) dissolved in it. Water is usually the solvent in these
Situations and will pass through the membrane until it reaches equilibrium, which
Is when the RATIO of solute(salts) to solvent(water) is equal on both sides. When
Equilibrium is reached, the two sides of the membrane have become isotonic.
isotonic
hypertonic/hypotonic
In our bath tub/ epsom salt example…
When you are in the bath, the solution inside your body is hypertonic to the
Bath water and the bath water is hypotonic to your body. When you stick your
Foot in epsom salts, the internal solution of your foot is hypotonic to the epsom
Salt bath and the epsom salt bath is hypertonic to your foot. If a single blood
Cell was placed in a bath like you, it would rupture. The cell could not control
The amount of water rushing into it by way of osmosis.
hypotonic
hypertonic
hypertonic
hypotonic
Epsom Salt Bath
Regular bath
7. Draw a chloroplast and label thylakoids and grana/granum.
Draw a mitochondrion and label inner membrane.
stroma
Chloroplast
Mitochondrion
8. Where do the light/calvin(light independent) reactions occur?
The light reactions happen in the thylakoid itself while the Calvin
reactions occur outside the thylakoid yet still inside the
Chloroplast in a space known as the stroma.
Where do the three steps of respiration take place? There are three
parts of respiration: 1)glycolysis, 2)Kreb’s cycle, and
3)electron transport (in order)
glycolysis occurs in the cytoplasm
Kreb’s cycle and electron transport happen in the mitochondria on
membranes known as cristae.
Rearrangement/shuffling of Carbons to yield/create :
Glycolysis, Kreb’s cycle (ATP), and Calvin Cycle(carbs)
Hopping of high energy electrons hot potato style along
membrane proteins to Yield ATP:
Light reactions and electron transport
9. What are the reactants and products of photosynthesis and
respiration? How are they related?
The relationship between photosynthesis and respiration is old
and absolutely dependent(symbiotic). The products from one
Become the reactants for the other and vice versa. It could be
Argued that it is the most important cycle for life.
Photosynthesis:
light
6CO2 + 6H2O

reactants
C6H12O6 + 6O2
products
Cellular Respiration:
C6H12O6 + 6O2 
reactants
6CO2 + 6H2O + energy
products
10.What is a controlled experiment? Explain what makes an
experiment “controlled”.
A controlled experiment has two groups: control and experimental
The control group does not have any experimental variables
Applied to it…in other words, it tries to set a baseline of results
To which the experiment can be compared. This is the essence
Of being a “controlled” experiment.
The experimental group is just like the control group except for
ONE thing…a variable. Usually this variable is directly related to
An hypothesis. Remember, an hypothesis is an untested but
Testable idea regarding an exploration into some unknown idea,
Property, behavior, etc..
For example, let’s say you hypothesize that Dr. Pepper will make plants grow
faster than water. Everything about your two groups would be the same,
from sunlight to soil to the amount of fluid poured on the plants AND the
species of plant themselves. The big difference would be that your control
group would use water as the fluid, and the experimental group would use
the Dr. Pepper.
11.When you design an experiment, how many factors are
tested in one experiment? Why is that important?
A well designed experiment will only test one factor at a time. To
Do otherwise would make it very difficult if not impossible to
Determine which factor was the one that was responsible for the
Result of the experiment.
Continuing with the Dr. Pepper example…if you also had an
Hypothesis that florescent bulbs provided better light for plants
Than sunlight. It would not be a good idea to test both of these
Factors at once because you would not be able to tell whether
It was the Dr. Pepper or the florescent bulb OR a combination
Of the two that was causing the result…
This is why I always laugh when contradictory nutritional studies
Appear in the news every other night…like drinking wine is good
For your heart—wait a minute, no its actually bad for your heart
And back and forth and back and forth.
12.Describe the difference between the experimental
manipulated (independent) and responding (dependent) variables.
The experimental or manipulated or independent(they are all
words for the same thing by the way) variable IS the experiment.
The responding or dependent variable(s) is the result of the
Experimental/manipulated/independent variable.
For our Dr. Pepper example, the watering with Dr. Pepper is the independent
variable.
Now…let’s say you run the experiment with the Dr. Pepper for two weeks. Over
Those two weeks you notice that the plant starts to wither and eventually you
See a fuzzy growth coming out around the base of the plant where it is in
Contact with the soil. Upon closer examination you realize that it is a fungus
That is damaging and consuming your plant.
The dependent variable in this scenario is what has happened to the plant…
Mainly the growth of a fungus and the subsequent wilting and death of it.
13.When an experimental hypothesis has been supported
by many different tests, it becomes a scientific __________.
THEORY
Most people use the word theory to describe an idea someone
Has come up with to describe a particular phenomenon. Some
People are logical about how they do this…some are magical
Or superstitious And some just make it up.
THIS IS NOT A SCIENTIFIC THEORY…SCIENTISTS HATE
IT WHEN SOMEONE TALKS SMACK ABOUT A SCIENTIFIC
IDEA AND TRY TO MAKE IT SOUND ILLEGITIMATE BY
SAYING THAT IT IS JUST A THEORY!!!!!!!!!
For example, evolutionary theory probably gets this treatment the most.
Scientists didn’t just arbitrarily pull this theory out of thin air. Many different
fields of science: immunology, cellular biology, geology, genetics, medicine, plate
Tectonics, microbiology, and others all independently arrived at the conclusion
that life evolves. The theory of evolution is literally used to save lives on a daily
Basis. In fact, evolution is what science calls a unifying theory since it explains
Many phenomena from a variety of different fields.
14.List the prefixes, from largest to smallest (kilo to milli) ,
and explain the process for converting from one to any other
Give three examples of this type of conversion.
Kilo-
hecto-
deca-
base
deci-
centi-
milli-
Decimal moves
One space to the…
.351kg
351g
3 to the left
23daL
.000673km
5 to the left
4 to the right
230,000mL
67.3cm
15.List and describe from largest to smallest, the ecological
levels of organization.
Biosphere – Layer around the Earth(15km or so) where all life
Exists
Ecosystem – An environment with specific group of biotic and
Abiotic factors.
biotic – living things and their influences
abiotic – non-living things and their influences
Community – In this level the focus is turned toward the living
Things in the environment and their specific relationships with
Each other. Food webs are a major focus.
Population - the study of groups of organisms that are of the same
Species. Scientists who study at this level have particular interest
In year to year fluctuations in population sizes due to disease,
Predation, or other factors. Evolution and genetics can also be studied here.
Organism – at this level, an individual creature is the focus. One lifetime
And one small but still significant existence
16.At which level does a food web operate?
Explain your reasoning.
A food web operates at the community level. Since we are simply
Observing the interactions, in this case energy transfer, between
Living creatures, it is definitely not at the ecosystems level…after
All, there is no need to consider the non-living environment. It can
Also not be at the population level since we need to consider
More than just one species of creature.
17.At which level does a nutrient like carbon operate?
Again explain your answer.
Carbon works at the ecosystem and biospere levels. Since we
are examining a non-living part of the environment, we cannot
stay at the Community level or lower since those levels only deal
with the living. Ecosystem attention to carbon would be on a
Smaller scale, like experimenting with carbon cycling in a certain
Species of plant. Biosphere Carbon study would be on a global
Scale like the greenhouse effect and global warming
18.What is a trophic level in an ecosystem/food web.
How do you determine what trophic level a particular organism
would be classified in?
Trophic levels are essentially
levels at which an organism
feeds. To determine what
level an organism is feeding
at, all one has to do is
consider the level of the food
that that creature is eating
and how far it is from the
initial source of energy. The
initial source of energy is the
sun and it is first accessible to
life in the primary producers
who exist in the first trophic
level.
5th Trophic Level
4th Trophic Level
3rd Trophic Level
2nd Trophic Level
1st Trophic Level
19.As you move up from one trophic level to the next, how
much energy from the lower level is available to the level above it?
20.Why/how does this happen? What happens to the rest
of the energy not passed on and up?
As one progresses through
the trophic levels
.01% Only 10% of the energy
from the previous level
reaches the next level.
.1% Although some of this
energy is used for life
1%
processes of organisms, the
majority of it is lost as heat.
One way to think of this is to
10%
consider how much energy
it takes to maintain body
temperature in mammals.
100%
21.Explain the differences between energy flow and nutrient
flow in an ecosystem/food web.
As was already stated, energy enters an environment through its
plants by photosynthesis. When plants are eaten by herbivores,
only ten percent of the original energy in the plants ends up in
the herbivores. When the herbivore is eaten by a predator, only
ten percent of its energy gets to the predator. As you can see,
energy slowly dissipates from the system as feeding levels get
higher and higher.
Nutrients, on the other hand, do not dissipate. Instead, they
CYCLE from one thing to another. For example, Carbon ping
pongs back and forth between photosynthesis in chloroplasts to
cellular respiration in mitochondria. Nitrogen can be in an
animal one moment…that animal dies and is decomposed by
bacteria which deposit the Nitrogen in the soil…then a plant
grows and sucks the nitrogen out of the ground into its
leaves…then an animal eats the plant and its nitrogen…
22.What is a limiting nutrient? Give an example and explain
what it limits and how it limits.
A limiting nutrient is usually a density dependent factor that has the potential
to limit, stall, or sometimes decrease the size of a population of organisms.
A good example can be found in most people’s front yards. A nice plush
lawn is prized by many homeowners. Lush and thick grass lawns require
ample supplies of nitrogen for vegetative
growth. New Mexico’s soil and climate does not lend to very high
concentrations of available nitrogen, so a gardener must fertilize(add
nitrogen) to artificially overturn the limiting factor/nutrient that is caused by
insufficient available nitrogen. Incidentally, this is why native grasses are
typically sparse and grow in little clumps rather than a uniform lawn. On top
of this, our soil is also limited in phosphorous and potassium as well…when
you buy fertilizer, there are three numbers 20-10-20(example) that refer to
the respective concentrations of these nutrients. Water is also a limiting
nutrient for many living things in New Mexico…that’s why they have evolved
lifestyles that are stingy with water.
23.Define density dependent factor and density independent
factor and give examples of each.
A density dependent factor affects a population in such a way
that there is a direct link to the population density of that
species of creature. In other words, these factors have a
greater or lesser affect depending on whether there are more
or less members of the population. Typically they are of biotic
origin. Examples: birds fighting for nesting sites, limited food
sources, disease travelling through a population
A density independent factor affects a population in the same
way whether there are millions of individuals in the population
or just one. Typically they are of abiotic origin. Examples: a
comet hits the Earth, Floods, drought
24.
Specifically, how do predators limit prey populations?
By eating them!!! More predators mean more hungry mouths to
feed. More hungry mouths leads to less prey(things to eat).
Eventually the prey population will decline as a result of this.
The whole thing is really a cycle because without enough food
to eat, the predators will then start to see a decline in their
numbers. After this happens for a while, the prey population will
start to rebound and grow in size.
25.Define exponential and logistic growth.
Make a simple graph of each and explain the differences.
Exponential – never ending growth of a population that
accelerates without boundaries…only occurs for short time
periods in nature.
Logistic – growth that may start out looking like it will be
exponential, but a limiting factor slows down the population and
growth slows or stops. This is the way that all natural
populations react in ecosystems.
exponential
logistic
26.Describe the “Greenhouse Effect” and explain how it
is necessary for life to exist on Earth.
Our atmosphere contains gases that trap solar energy, especially
Infrared and visible light wavelengths…this is the greenhouse
effect. It allows the Earth to be warmer than it would otherwise
be without an atmosphere. This is the biggest problem with Mars
supporting life like that found on Earth since it doesn’t have an
atmosphere.
Without the greenhouse effect, the Earth would be much colder
and would experience very large fluctuations in temperature on a
daily basis. Some life forms, like bacteria, could probably deal
with this, but most life relies on consistent temperatures to
survive.
27.What is the difference between biotic and abiotic factors
in an ecosystem? Give three examples of each.
Biotic factors- living parts of the environment(plants, animals,
fungi, bacteria, and how they affect everything else in the
environment)
Abiotic factors – non-living parts of the environment(soil, water,
sun, wind, chemistry of each of these, temperature, and how
they affect everything else in the environment.)
28.
Define ecological succession.
29.What is primary succession, and how does it differ from
secondary succession?. Give an example of when or under
what circumstances this occurs.
Succession is the dynamic series of events that occur as an
ecosystem forms and changes over time. An ecosystem is
different when it is 10 years old vs. 100 years old vs. 1,000 yrs old
and those changes are what succession attempts to define.
Primary – when an ecosystem develops where there was nothing
there before it. Receding glaciers, volcanic islands or lava flows,
the greatest example occurred when the Earth cooled after
forming.
Secondary- when an ecosystem is destroyed or severely
damaged and then grows back. Forest fires, floods, human
activities like: logging, construction, engineering cause this to
happen.
30.Describe, explain in what ways plants are involved in the
water cycle.
Plants are involved in the water cycle in two related ways:
Water uptake- the act of pulling water out of the ground
begins a sub-cycle of the water cycle that involves plants
Transpiration- the evaporation of water through the leaves of
plants…interestingly, this is what allows them to draw water
out of the ground in the first place. It increases the humidity
of the surrounding air and in some cases(rain forests) it can
cause precipitation.
31. Make a table summarizing the following information:
a.
the name of the three most well-known subatomic
particles,
b.
the charge for each of these particles,
c.
where in the atom each of these particles is located.
32.Draw a simple diagram of an atom, showing the location of
each of the three particles from above.
Nucleus
Protons/
neutrons
electron
33.
Draw and label a simple atomic model for a water molecule.
34.What is polarity in a molecule? Explain why water is a
polar molecule.
Polarity in a molecule simply
means that it has a positive and
a negatively charged region.
Negative
charge
Oxygen has 8 electrons and
oxygen
each hydrogen has 2. When
they form a covalent bond, the
2 electrons from the hydrogen
are unevenly shared with the
oxygen holding on to them
hydrogen
hydrogen
more. Since electrons are
negatively charged, this makes
Positive charge
the oxygen end of water take
on a negative charge. The end
with the hydrogens take on a
positive charge since they have
the electrons less often.
35.Define cohesion and adhesion.
As a result of its polar nature, water is a pretty sticky molecule,
like a magnet. When water molecules stick to other water
molecules it is called cohesion. This allows water to create
surface tension. This also helps water resist evaporation.
When water molecules stick to other molecules…say a piece of
glassware like a graduated cylinder, it is called adhesion. This
property creates the meniscus(curved line) that you must know
how to read when using a graduated cylinder.
36.What is a solution. Explain what part of a solution is the
solvent, and what part is the solute. Give an example.
37.Why is water such a good solvent?
Salt water is a solution most people are familiar with. It has
definite proportions of sodium chloride(NaCl) and water(H20).
The solvent in the solution is water and the solute is the NaCl.
The reason water is such a good solvent is that it is polar. The
negative(oxygen) end of water tends to attract positive molecules
and the positive(hydrogen) end of water tends to attract negative
molecules. In the case of a salt like NaCl that has a weaker ionic
bond(electrons aren’t really shared), the water molecules literally
rip apart the bond that holds the sodium(Na+) from the
chlorine(Cl-). This effectively dissolves the solute in the solvent.
The process can be reversed by evaporating the water…this
decreases the number of water molecules that can effectively
hold apart the Na+ and Cl- atoms which then reunite in NaCl.
38.
39.
What is the definition of an acid?
What is the definition of a base?
An acid or acidic substance is a solution that contains a higher
concentration of H+ ions(sometimes called hydronium) than
OH- ions.
A base or alkaline substane is a solution that contains a higher
concentration of OH-(hydroxide) ions than H+ ions.
You should note that if there are equal amounts of H+ ions and
OH- ions, you would have plain water…which is neutral…neither
a base nor an acid.
40.What is the pH scale? What does it measure, what is the
range of values for acids and bases, and what is the relative
strength when comparing one number to another?
The numbering system for the
ph scale is logarithmic. This
means that every
integer/number actually
represents 10x the preceding
number.
For example, battery acid is
ten times more acidic than
lemon juice AND 100 times
more acidic than vinegar.
All are referenced to a neutral
pH of 7 which is the ph of plain
water.
41.What is a carbohydrate? How are carbohydrates used
by living organisms?
Carbohydrates are 6 carbon molecules shaped in a hexagon that
are a combination of CO2(carbon dioxide) and H20(water).
Carbohydrates are the storage form for
energy captured during photosynthesis.
This is then passed on through food webs to
all the living things on the planet.
42.What is a protein?
How are proteins used by living organisms?
Proteins are chains of molecules called amino acids. They are
very complex molecules that can take on an almost infinite
number of shapes. These shapes allow them to function as
catalysts for chemical reactions. The chemistry of life is driven
by protein catalysts called enzymes.
some amino acids…
43.
What is a lipid? How are lipids used by living organisms?
Lipids, also known as fats, are excellent storage molecules for
energy. Most animals have a certain amount of their body that
consists of fat/lipids. It is excellent at this because it stores
more energy in less mass than any of the other organic
molecules…basically they are energy dense. In fact, gram for
gram, they contain more than twice the energy than
carbohydrates or proteins.
Phospholipids are a special class
of lipid that make up the cell
membranes every life form. They
are special because they have a
hydrophilic and hydrophobic end.
This allows them to form a
bilayer membrane that can easily
interact with water environments,
be semi-permeable, yet strong.