BIOL 101L midterm Flashcards
process of science
a way of gathering and testing information used by many people
a hypothesis must be…
testable
an experiment should be..
repeatable
objective observations
those that can be verified- repeated and consistently interpreted by different observers
subjective observation
they are observer specific and may not be interpreted in the same way by everyone
hypothesis
a tentative explanation of cause and effect based on underlying observed phenomena
independent. variable
the variable being changed
dependent variable
the variable being measured
control
where all the factors are the same as the test group, except the factor being tested is left in its normal, unmanipulated state
protocol
the description of steps in a scientific investigation
prokaryotic cells
lacks a nucleus and other membrane-bound organelles. Contains a nucleoid region contains DNA. prokaryotic contain ribosomes and various internal membranes
Prokaryotes
the term applied to organisms with prokaryotic organization. Found only in bacteria and archaea. generally unicellular. Some prokaryotes such as bacteria, have a cell wall and can use flagella for motility.
eukaryotic cells
have a distinct nucleus thats surrounded by a nuclear membrane. has membrane bound organelles.
when looking at a eukaryotic cell through a light microscope which organelles are easily identifiable?
nucleus, chloroplasts, cell wall, and other large plastids
which organisms lack membrane- bound organelles
prokaryotes
what role do bacteria play in the soil
they play an important role in nitrogen fixation
what is nitrogen fixation
converting nitrogen from the atmosphere into a form that can be used by plants
what is bacterias role as decomposers
they break down dead plants and animal and return the organic material to the system to the be used by other organisms.
are bacteria used in the production of foods such as cheese and yogurt
yes
are bacteria responsible for spoiling food and diseases
yes
Photosynthetic bacteria
use light as their energy source in a process similar to photosynthesis in plants; they don’t use water as their source of electrons for their photosynthetic process.
chemosynthetic bacteria
obtain their energy from the oxidation(loss of electrons) of inorganic substances
3 group of bacteria
bacilli, rod shaped; cocci, small sphere; spirilla, corkscrew-shaped
blue-green algae
photosynthetic; unlike other photosynthetic bacteria, but like photosynthetic eukaryotes these algae possess pigment chlorophyll a
unicellular form
completely independent of one another
multicellular
theres a lot of cell differentiation. Ex. eye cells, heart cells, skin cells
colonial cells
does not have a lot of cell differentiation; if you cut up a colonial cell it will act as independent cell
kingdom fungi
eukaryotic, heterotrophic , and generally multicellular.
paramecium
unicellular
kingdom: protista
phylum: ciliophora
E or P: eukaryote
location of genetic info: micronucleus and macronucleus
type of movement: cilia
what organelles are seen:
euglena
unicellular; photosynthetic and heterotrophic
kingdom: protista
phylum: euglenophyta
E or P: E
location of genetic info: nucleus
type of movement: flagellum
what organelles are seen: nucleus, contractile vacuole, chloroplasts,
volvox
colonial cell; photosynthetic
kingdom: protista
phylum: chlorophyta
E or P: E
location of genetic info: nucleus
type of movement: 2 flagellum to move
what organelles are seen:
amoeba
unicellular; heterotrophic
kingdom: protista
phylum: amoebozoa
E or P: E
location of genetic info: nucleus
type of movement: pseudopods- fake feet
what organelles are seen:
elodea
multicellular; photosynthetic; moves though plasmolysis
kingdom: plante
phylum: magnoliaphyta
E or P: E
location of genetic info: nucleus
type of movement: cytoplasmic stream
what organelles are seen: chlorophyll, nucleus, contractile vacuole, chloroplast
Human epithelium
multicellular; heterotrophic
kingdom: animalia
phylum: chordata
E or P: E
location of genetic info: nucleus
type of movement: N/A
organelles seen: nuclei
oral groove
appears as a fold on one long side of the paramecium; fluid and food particles are forced into the oral groove
cytopharynx
the lower end of the oral groove, as food particles accumulate at the lower end of the groove a food vacuole forms enveloping the food particles
anal pore
where the food vacuole attaches to and empties its contents
contractile vacuole
removes excess fluid from the cell
What happens when a paramecium cell encounters an immoveable object
it reverses direction and backs away. This behavior is triggered by a change in electrical charge due to the influx of calcium ions into the cell. This change causes the cilia on the paramecium to reverse the direction of the beating
macronucleus
controls the cell maintenance functions
micronucleus
responsible for genetic and reproductive functions including producing the macronucleus
phagocytosis
the ability to surround and ingest food particles
can a euglena be made heterotrophic? and if so how?
yes it can by being kept in the dark for a prolong period of time
do euglenas have a cell wall?
no
how does the cell of a euglena keep its shape
it retains its shape due to the presence of a pellicle, which is a layer of elastic proteins inside the cell membrane
flagellum
a whiplike structure that helps the cell move
stigma
a light sensitive structure containing pigments known as carotenoids
pyrenoids
organelles in the euglena that are associated with the chloroplasts, they are involved in carbon fixation, starch formation, and storage
What are paramylons
they are made in the pyrenoids and are similar to starch they enable the euglena to survive in low light conditions
what allows the volvox colony to move
the cells on the outside of a volvox colony are biflagellate and the coordinated beating of the flagella allow the colony to move
cytoplasmic strands
the outer cells of the volvox are connected to each other by cytoplasmic strands.
cilia
tiny hair-like structures made of microtubules that often cover the entire surfaces of cells.
are cilia only used as a locomotory device?
no, they can also be used to push food into the oral groove of a paramecium, and can push up mucus-trapped dirt in the respiratory system of humans.
psuedopodia
a type of movements where microtubules are extended forward from the body and pull the rest of the cell along.
plastids
an organelle found in plants that perform a variety of functions including manufacturing and storage of foods
endosymbiont theory
implied that chloroplast and mitochondria were once prokaryotic cells that were engulfed by, and through evolutionary processes, developed a symbiotic relationship
plant vacuoles
can be found abundantly in elodea and may be filled with waste products, enzymes, pigments, or other material play a role in cell turgor
cytoplasmic streaming
how elodea move. chloroplasts are suspended in the cytoplasm, moving throughout the cell,
plasmolysis
cellular shrinkage occurring as a cell is exposed to a hypertonic solution. Can be examined in an elodea cell under a microscope
phylogenetic tree
shows the relationship among the organisms. The branches represent the lineages of organisms
Nodes- represent the most common ancestor between or among the lineages that connect there.
what is overall equation for photosyntheis
H2O + CO2 –> C6H12O6 + O2
Light is used as the energy source
thyalkoid membrane
where the absorption of light takes place
stroma
the fluid within the chloroplasts where the carbohydrate formation takes place
photoreceptors
absorb light energy
what are the 2 groups that chloroplasts can be divided into?
chlorophylls and carotenoids
chlorophylls
occur as greenish pigments in all photosynthetic plant tissues and capture light for photosynthesis.
how many types of chlorophylls are there and how are they differentiated?
there are at least 5 kinds of chlorophylls that have the same basic structure. They have the same chemcial structures however they differ in subsitutions of one molecular group for another. The
different molecular group makes it so that the chlorophyll absorbs light at a different wavelength
how do the chlorophylls differ from one another?
they differ in the wavelength they absorb, solubility in water, and polarity
chlorophyll a
blue-green pigment
occurs in all photosynthetic eukaryotes and cyanobacteria
chlorophyll b
olive-green pigment
in most but not all plants
is an accessory pigment
accessory pigment
captures additional light energy which is then transferred to chlorophyll a
chlorophyll c
found in certain kinds of algae while others are confined to certain bacteria
carotenoids
class of yellow, orange, or red pigments.
function of carotenoids
accessory pigments in photosynthesis and as coloring in reproductive parts to enhance pollination and fruit dispersal
2 groups of carotenoids
carotenes and xanthophylls
B-carotene
a yellow- orange pigment: an essential dietary supplement in animals
its chemically modified by hydrolysis to form vitamin A
xanthophylls
the other 3 pigments that can’t be separated by chromatography in lab because they are so similar
paper chromatrography
a method used to analyze pigments
hoes does paper chromatography work?
a mixture containing pigments ia applied to a sheet of paper which is then exposed to a solvent. As the solvent moves up the paper different pigments are separated form each other at different rates
Rf value
reference front; it is the distance a compound moves during chromatography, relative to the solvent front, and reflects the relative affinity a substance has for the solvent
polar molecules on paper chromatogrpahy
polar molecules adsorb to the polar chromatography paper and do not move
nonpolar molecules on paper chromatogrpahy
travel with the solvent
adsorb
means to adhere to the surface of another compound w/o forming a chemical bond.
formula for Rf
Rf= distance substance traveled from origin/ distance solvent travels from origin
what is the order from origin to solvent front of the major pigments found in plants?
chlorophyll b, chlorophyll a, the 2 xanthophylls and B-carotene. Chlorophyll B is the most polar and stays toward the bottom at the origin and B-carotene is the most nonpolar so it travels the farthest
chromatogram
complete array of colored bands
what did Robert Hill show about chloroplasts
Robert Hill showed that water can operate in the presence of light and an electron acceptor to release oxygen
in the hill reaction where did the oxygen given off come from, since there was no CO2 present?
the water
the hill reaction showed what about the photosynthetic reactions
it showed that the photosynthetic reactions giving up oxygen were different than the ones using CO2. It separate the “photo” and “synthesis” part.
what did the hill reaction show about the oxidation-reduction reactions
it showed that the redox reactions are initiated by light and are an integral part of photosynthesis. It represents the converting of light energy to chemical energy
what happens to electron in the chloroplast during photosynthesis?
they are boosted to a higher energy level and are absorbed by leaf pigments
reduced
electrons are being absorbed/ gained
oxidized
electrons are being lost
is water oxidized or reduced in photosynthesis.
the water is oxidized
is carbon dioxide oxidized or reduced in photosynthesis
carbon dioxide is reduced
what is NADP+
its a cofactor thats used during the photosynthetic process
What does NADP+ do?
its a cofactor that picks up electrons and becomes NADPH
what is NADPH
its a resource used for the light-independent reaction during photosynthesis.
how can you detect the process of NADPH being reduced
use a dye that intercepts these electrons, and the change of color will indicate the flow of electrons. Which would be an indicator for photosynthetic reactions
what is the role of DPIP in the hill reaction
it replaces the NADP+, electron receptor molecules
what happens when DPIP is incubated with photosynthesizing chloroplasts
it changes from blue to colorless, indicating a flow of electrons
formula for NADP+ accepting electrons
2NADP+ + 2H2O –> 2NADPH + O2 + H+
formula for DPIP in water
2DPIP+ 2H2O–> 2DPIPH + O2
formula for DPIP accepting electrons
DPIP(blue) + e- –> DPIP( colorless)
what level is the spectrophotometer set at in the hill reaction and why
the spectrophotometer is set at 605 nm because thats the wavelength that blue DPIP absorbs at. This is also when the difference in rate of transmittance is the highest
what must happen before using the spectrophotometer
the instrument must be set to 100% T by using the calibration tube.
why is the calibration tube used
to give us a baseline reading before each measurement
why are the spinach leaves deveined
because the stem don’t have chloroplasts in them
why were the spinach leaves put in the fridge and chilled blender
to stunt the rate of photosynthesis
why was a chilled 0.5 M sucrose solution added
it was chilled to stunt the rate of photosynthesis. It was a sucrose solution because sucrose was a good isotonic solution to use
why was the solution blended in short 3 10 second bursts
because the blender generates heat, so doing it in short bursts allowed photosynthesis to be stunted
why was the solution poured through 3 layers of cheesecloth?
to separate any chunks
what were the boiled chloroplasts used for
they were used as a control group. The boiled chloroplasts were assumed not to photosynthesize
one sample, in the hill reaction, was kept in the dark , why?
to have a control for the effect of light
why is buffer needed in the experiment?
to neutralize the pH, allowing for optimal pH
what is a gram stain used for
its used to identify bacteria
why use gram stain
because bacteria have strong cell walls that surround the cell membrane and provide a protection. the gram stain allows gram-positive cells to be differentiated from gram-negative cells. The gram stain identifies bacteria b y differences in cell wall structure
gram- positive cell
the cell wall that is thick and stains purple since the cell wall retains the gram stain.
the color will be purple
gram- negative cell
its thinner and partially dissolved and does NOT retain the gram stain
the color will be red or pink/ colorless
how does the gram stain work
the gram stain is an organic compound that stain the cell wall when the bacteria are immmersed in the stain. The amount of stain left in cell wall will depend on structure of the wall.
oscillatoria
prokaryotes
domain bacteria
colonial organisms
filaments
photosynthesize
gleocapsa
unicellular
often cluster
gelatinous sheath
lactobacillus
present in yogurt
consumes lactose and converts milk to yogurt
rod-shaped chains
yeast
eukaryotes:kingdom fungi
used to make alcohol and bread
diffusion
molecules move from high concentration to low concentration until equilibrium
osmosis
the movement of water moving from a high potential to a low potential until equilibrium
plasmolysis
cellular shrinkage in a hypertonic solution
water flows out of a central vacuole
