Bio Comp Flashcards
What is an independent variable, dependent variable, control variable?
In an experiment, the independent variable is the variable that is varied or manipulated by the researcher, and the dependent variable is the response that is measured. An independent variable is the presumed cause, whereas the dependent variable is the presumed effect. The control variable is a variable that remains unchanged or held constant to prevent its effects on the outcome.
If you are trying to determine whether heating water allows you to dissolve more sugar in the water then your independent variable is the temperature of the water. If heating water affects the amount of sugar you can dissolve, the mass or volume of sugar (whichever you choose to measure) would be your dependent variable.
How do you formulate a hypothesis? What is the purpose of the hypothesis?
Ask a question. A possible answer to the question.
What are the 7 characteristics of life?
(GRADERM)
1) grow and develop
2) reproduce
3) adapt/evolve
4) diverse
5) exchange matter
6) respond to stimuli
7) made of cells
What makes a molecule a macromolecule?
They are big
What is the relationship between polymers and monomers?
Polymer means many monomers. Sometimes polymers are also known as macromolecules or large-sized molecules. Usually, polymers are organic (but not necessarily).
Why are carbohydrates, nucleic acids, and proteins considered macromolecules?
They are polymers
Why are lipids not technically considered macromolecules?
Lipids are not technically macromolecules, because they’re not built in the same way—they’re not polymers made up of individual subunits called monomers. But they are sometimes considered as part of that family, and they are pretty important molecules in the cell.
What is the molecular ratio of all monosaccharides?
CH2O
What is the main monosaccharide used by all organisms?
carbohydrates
What is a disaccharide and a polysaccharide?
disaccharide - 2 sugars bonded together
polysacharide - are polymers of monosaccharide
Give the 4 main polysaccharides, their function, and in which organisms they are found
starch (plants), cellulose (plant cell walls), chitin (fungi cell walls), glycogen (humans)
Lipids contain hydrocarbons. How is a hydrocarbon different from a carbohydrate?
There is no ratio and low oxygen
Hydrocarbons contain hydrogen and carbon only (e.g methane CH4). Carbohydrates contain carbon combined with an oxygen and hydrogen in the ratio which they occur in water. (e.g. glucose C6H12O6).
What are the 4 main types of lipids and their functions?
steroid - chem. message, hormones
tryglyceride - fat and oils
waxes - waterproofing
phospholipids - cell membrane
Differentiate between saturated and unsaturated lipids. There are 5 key differences
Saturated:
1) all C bond to H
2) No C = C
3) double bonds
4) saturated with H long
5) straight change, solid at room temp.
Proteins are the polymer of what?
amino acids
What is the quality of proteins that allow them to perform the work of a cell?
They have the ability to change their shape
What is the function of an enzyme?
speeds up reactions
What is activation energy?
energy needed to start a reaction
What is a substrate?
reactant when using an enzyme
What is the part of an enzyme that the substrate binds to?
Protein enzyme
What happens to the enzyme after the reaction?
returns to its original shape
What are the 2 patterns of the naming of enzymes?
molecule it’s using plus “-ase”
Nucleic acids are the polymers of what?
nucleotides
What is common with all monomers of nucleic acids? There are at least 5. (only found three)
both nucleotides, made of sugar phosphate, nitrogenous bases
What are 3 key differences between DNA and RNA?
DNA: deoxyribose, thymine, 2 strands
What is the formula for water?
H2O
What bonds hold these atoms together in a single water molecule?
covalent bonds
Covalent bonds are a type of _____ force
weak force
What does the term electronegativity refer to?
The pull of a nucleus on its outer most electrons
Which element of water is most electronegative?
oxygen
Which element in water will have a slightly negative charge? A slightly positive charge?
Hydrogen: slightly positive
Oxygen: slightly negative
The difference in chrage across a molecule gives the molecule the property of being ____
polar
This property makes the molecule act like a small weak______
magnets
What does hydrophilic mean? What does hydrophobic mean?
hydrophilic - likes water
hydrophobic = hates water
Water can make what kinds of bonds between other water molecules?
hydrogen bonds
What kind of force are hydrogen bonds?
They are a type of intermolecular force
What is cohesion?
Cohesion allows substances to withstand rupture when placed under stress
What is surface tension?
cohesion at the surface of water
Water can make what kinds of bonds with other hydrophilic molecules?
hydrogen bonds
What is adhesion
adhesion is the attraction between water and other molecules.
The process of a hydrophilic fluid climbing up a tube and bringing other water molecules with it is known as….
capillary action
What 2 properties can make the fluid move farther up the tube on its own?
thinner tube and more polar
Because water molecules “stick” to each other, it takes extra energy to separate them and get them to speed up. Because of this water has high _______
concentration
What is heat vaporation?
water’s ability to store heat at moderate body temperature and climate
pH measures the concentration of what in a fluid?
acidity - acidic, neutral, basic
What pH are acidic, neutral, and basic?
acidic: 1-6
neutral: 7
basic: 8-14
How many times more acidic is a pH of 1 vs 2? vs. 3? vs. 7? vs. 9? vs. 14?
10^-2, 10^-3, 10^-7, 10^-9, 10^-14
What are Robert Hooke and Aton von Leeuwenhoek’s contribution to our knowledge of cells?
The cell theory
What are the 3 components of cell theory?
1) all organisms are made of one or more cell
2) cells are the basic unit of life
3) cells come from existing cells
Why are cells small?
Food and waste must pass through the cell surface
How do you calculate the surface area: volume ratio of a cubic cell?
.
What happens to the surface area of a cell as a cell increases in size?
it gets bigger
What happens to the surface area: volume ratio as a cell increases?
It gets smaller
What are the components of prokaryotic cell?
cell membrane, ribosomes, cytosol, single circular chromosome, cell wall, flagela, nucleotide
What is missing from prokaryotic cells?
Prokaryotes have no organized nucleus.
What are the 2 domans of prokaryotic organisms?
bacteria, archea
Compare the number of cells in a prokaryote with eukaryote?
prokaryotes are single celled
eukaryotes are multicellulared
What is the main advantage with being multicellular?
cell specialization
What is the composition of the cell membrane?
phopholipid bilayer
Describe the parts and qualities of those parts of a single phosolipid?
head = polar tail = nonpolar
What are all of the organelles and cell structures that can be found in eukaryotic cells and give the function of each?
.
What are the properties of a phospholipid?
hydrophillic head, hydrophobic tail
How are phospholipids arranged in a biological membrane?
heads near water, tails covered by head
What particles can diffuse directly through the phospholipids of a membrane?
small particles
What are the 2 key characteristics of passive transport?
doesn’t require energy
high concentration to low concentration
Describe the phenomenon of dynamic equilibrium
both concentrations are the same, but still moving
What is meant by simple diffusion? Give an example
nonpolar particles pass through the cell membrane
What is meant by facilitated diffusion? Give an example
The membrane has a channel and carrier proteins that allow large polar particles or ions to pass through the membrane
Define the terms hypotonic, hypertonic, and isotonic. How does water move when the solution is any of these conditions? How does water move when the cell is any of those conditions?
hypertonic - high concentration outside of cell
hypotonic - low concentration outside
isotonic - same concentration within cell and out/off diffusion
What will be the condition of a cell when placed in hypotonic, hypertonic, and isotonic conditions of solution?
hypertonic - cell shrinks
hypotonic - grow
isotonic - stays the same
You have a cell in an isotonic solution. How do you make the potato hypotonic to the solution? How do you make the potato hypertonic to the solution?
hypotonic = adding salt
hypertonic - decreasing salt
What will prevent a plant cell from lysing, a fungal cell from lying, a protozoan from lysing, and an animal from lysing if too much water enters the cell?
plan cell - cell wall
a fungal cell - chitin
a protozoan - contractil/vacuole
animal - epidermis
How do O2 and CO2 diffuse in respect to the blood in your lungs? How do O2 and CO2 diffuse in respect with the blood near your muscle cells?
O2 goes to blood
CO2 does opposite
What are the 2 key characteristics of active transport?
requires energy
low concentration to high concentration
How is ATP related to active transport?
ATP is the energy used for active transport
What are the 3 main types of active transport? Describe each and how each affects the cell membrane.
protein pumps, exocytosis, endocytosis
Draw and label the 3 distinct parts of an ATP molecule
.
What is adenosine? What is the difference between ATP and ADP? Where is the usable energy stored in ATP?
adenine + ribose.
ATP = 3P ADP = 2P
What is ATP directly used to do? Give an example.
Change the shape of proteins
Differentiate between autotrophs and heterotrophs
Autotrophs - generates energy without consuming other organisms
Heterotrophs - rely on other living organisms to generate energy
Differentiate between producers and consumers
producers - autotrophs
consumers - heterotrophs
What is the complete balanced equation for photosynthesis?
6CO2 + 6H2O –> C6H12O6 + 6O2
What is the ultimate source of all energy found on Earth?
sunlight
Be able to draw chloroplast: photosynthesis diagram from memory
.
What are the 3 main stages of the Light Reactions?
P.S. II –> ETC –> P.S.I
What is the overall purpose of the light reactions?
create 6O2, ATP, and NADPH for the calvin cycle
What are the main purpose of the Calvin Cycle?
To create NADP+, ADP+P, and C6H12O6
Why are plants green?
They absorb all the colors of the spectrum, but reflect green
What are the 4 main factors that determine the rate of photosynthesis and what do their graphs look like?
.
Why does excessive heat cause the rate of photosynthesis to go down?
The proteins used denature and change their shape
Compare cellular respiration to photosynthesis with regards to the following things: energy, CO2, O2, glucose, H20, and the equation
Cellular respiration - releases energy, CO2 released, O2 used, uses glucose, H20 released
Photosynthesis - stored energy, CO2 keeps, O2 releases, makes glucose, H2O used
What is meant by the term anaerobic respiration?
anaerobic respiration doesn’t require oxygen
What are the 2 steps of anaerobic respiration in order?
Step 1) glycolysis
Step 2) fermentation (alcohol, lactic acid)
What are the 2 types of fermentation steps? What organisms perform each?
Lactic acid fermentation and alcohol ferementation
What organisms perform glycolysis?
plants
What is the purpose of performing glycolysis?
To create sugars (glucose)
Which type do humans perform, which parts of humans perform it, and why would humans perform it?
lactic acid fermentation
muscles
to slow us down
Why is cellular respiration also called aerobic respiration?
requires oxygen
What are the 3 steps in order of cellular respiration?
glycolysis –> Krebs cycle –> ETC
What are all of the inputs and NET outputs of glycolysis?
inputs: glucose
outputs: 2NADH, 2 pyruvate, 2 ATP
Where does glycolysis take place?
mitochondria
What are all of the inputs and the NET outputs for glycolysis for per 1 molecule of glucose?
glucose, 2 ATP, 4 ADP, 2 NAD+ –> 2 pyruvate, 2 ATP, 2 NADH
Where specifically does the Krebs Cycle take place?
In the matrix of the mitochondria
What are the inputs and outputs for the Krebs Cycle per 1 molecule of glucose?
inputs: 2 pyruvate
outputs: 2 FADH, 8 NADH, 2 ATP, 6CO2
What is the main purpose of the Krebs Cycle?
regenerate electron carriers for the etc.
Where specifically does the Electron Transport Chain take place?
cell membrane
What are the inputs and outputs of the ETC per 1 molecule of glucose?
inputs: 2 NADH, 6O2, 2 FADH, 8 NADH
outputs: 32 ATP, 6H20
Describe the steps of the ETC, both in reality and with waterwheel analogy
.
What is the ETC made of?
proton pumps
What powers it?
electrons
What is the benefit of the mitochondria having 2 membranes?
movement in the 2 membranes
Why is the inner membrane (cristae) folded?
want more etc.
ATP synthase performs what 2 functions?
enzyme and a proton channel
What is the function and purpose of O2 in aerobic respiration?
takes electrons and protons after use
How much more ATP is generated in aerobic respiration versus anaerobic respiration?
aerobic - 36 ATP
anaerobic - 2 ATP
How many times more ATP is generated in cellular respiration vs. anaerobic respiration?
18x
Where would the ETC be located on a prokaryote?
cell membrane
What is the origin of the mitochondria? How is the mitochandria different from its ancestor?
both prokaryotes that were brought in by hosts cells
What are the 4 main reasons why cells reproduce? Explain each.
S.A.: V
DNA overload
repair and replacement
browth
What is meant by the term “asexual reproduction”?
offspring is genetically identical to the parent
What are the 3 main forms of asexual reproduction?
budding, fragmentation, binary fission
What is an organism’s genome?
total of all of its gene
How is a genome contained in a prokaryotic cell?
in a single circular chromosome
How is a genome contained in a eukaryotic cell?
many or linear chromosomes
Where is genome contained in prokaryote?
nucleoide
Where is a genome contained in a eukaryote?
nucleus
What is the process by which prokaryotes asexually divide?
binary fission
In prokaryotes, DNA is found alone. In eukaryotes the DNA is coupled with _____ to create a material called ________
histones, chromatin
A single strand of chromatin is called
chromatid
What is a chromosome? What are its 2 varieties? Draw out both of them
structures made of chromatin, \, x
What is meant by a cell being diploid?
contains 2 of each chromosome
Why are your human somatic (body) cells diploid?
1 of each chromosomes will be passed down to the offspring
What are the 2 main divisions of the cell cycle?
meiosis and mitosis
What are the 3 parts, in order, of the 1st part of the cell cycle, and what happens in both?
interphase
G1, S, G2
Name and describe the 2 parts of cell division (m-phase)
mitosis and cytokinesis
What are the 4 phases in order of mitosis and what happens in each?
- prophase
- metaphase
- anaphase
- telophase
Draw a cell interphase and in each phase of mitosis
.
How is cytokinesis different from mitosis?
mitosis is division of nucleus/ cytokinesis is division of the cytoplasm
How does cytokinesis happen in animals? In plants?
animals - membrane pinches
plans - builds cell plate
What regulates the timing of the cell cycle?
cyclins
Describe anchorage and density-dependence with respect to the cell cycle?
density = dependence = once cell is at max density cell stops dividing
Growth factors are chemicals secreted by a cell to make other cells around it grow. When would a cell secrete these growth factors?
growth and development or repair
What is heredity?
passing genes to offspring
What is genetics?
study of heredity
What is trait?
characteristics
What is a gene?
factor that controls a trait
What is an allele?
variation of a gene
What is a genotype?
the alleles
What is a homozygous?
both alleles are same
What is a heterozygous?
alleles differ
What is true-breeding?
homozygous
What is hybrid?
heterozygous
What is a phenotype?
trait
How do dominant and recessive alleles interact?
dominant - expressed recessive - suppressed
What is the dominant eye color in humans? What geneotypes will code for its expression?
brown widows peak (?)
What type of hair line is dominant in humans? What geneotypes code for it? Which is more common?
black
r - flat hairline (?)
What does it mean when a trait is said to be controlled by Incomplete dominance? Give an example?
The 2 traits are blended
What is mean when a trait is said to be controlled by co-dominance? Give an example.
both alleles are expressed equally
Be able to construct a Punnett square.
.
Compare Segregation to Independent Assortment:
.
What is the function of DNA?
has genetic information
What are the 3 components of a nucleotide?
A sugar (called deoxyribose)
A Phosphate (1 phosphorus atom joined to 4 oxygen atoms)
One of 4 bases (Adenine, Guanine, Cytosine, Thymine)
Which component of a nucleotide can change between different nucleotides?
.
What is the purpose of the sugar and phosphate?
provide backbone of a DNA strand
Compare Purines and Pyrimidines. How many nitrogenous rings are on each? Which bases are classified as which?
Purines: Adenine and Guanine
Pyrimidines: Cytosine and Thymine
Which bases can pair with each other in the double strands of DNA?
A=T
C=G
Be able to calculate base frequencies with Chargaff’s rule
% Adenine = % Thymine
% cytosine = % Guanine
What is the shape of a strand of DNA?
double helix
What causes the DNA to twist?
hydrogen bonding
What are the proteins that bind to DNA in a eukaryote chromatin?
histones
What is a nucleosome?
DNA wrapped around a group of histones
What is meant by the term supercoil?
nucleosomes that are coiled around each other
When does DNA replicate in the cell cycle?
.
What are the 3 steps of replicating DNA?
- unzipping
- base pairing
- double checking
What is the purpose of unzipping?
DNA helicase unzips the double helix strand of DNA
What enzyme is used in unzipping?
.
How are new nucleotides added in base pairing?
Free nucleotides are added to both new single strands of DNA by DNA polymerase
What enzyme is used in base pairing?
DNA polymerase
What is the purpose of double checking?
The DNA polymerase can double check the strand to correct any errors in base pairing
What enzyme is used in double checking?
DNA polymerase
What would be the problem if DNA was always replicated with 100% accuracy and precision?
we would all be the same
What is the error rate of DNA replication?
1: 100 million
Using the error rate of DNA replication, how many errors would you expect in a human cell that contains 3 billion nucleotide base-pairs?
30
What is a replication fork?
sight where unzipping takes place
The two strands made from replication fork will be what to each other?
identical
Define transcription
DNA transcription is a process that involves transcribing genetic information from DNA to RNA (In other words, an RNA copy of a gene sequence is made during transcription.) The transcribed DNA message, or RNA transcript, is used to produce proteins.
Define translation
Translation is the process of translating the sequence of a messenger RNA (mRNA) molecule to a sequence of amino acids during protein synthesis.
Describe the term semi-conservative
Each daughter stand of DNA are half of the parent strand
Why is it acceptable that human cells gain mutations every time they go through the cell cycle? (Give 3 reasons)
1) less than 5% are genes
2) each cell uses some genes
3) some mutations don’t change proteins
Define the term gene expression
Gene expression is the process by which information from a gene is used in the synthesis of a functional gene product. It is the process by which the information contained within a gene becomes a useful product.
What molecules do the work of the cell?
Proteins do most of the work in cells.
DNA is used to directly make what product?
proteins
Where does transcription take place?
cell nucleus
What happens to introns and to exons after mRNA is made?
During the process of RNA splicing, introns are removed and exons are put back together.
mRNA is used by what cellular structure?
ribosome
What 2 places can ribosomes be found?
Free ribosomes are found in cytosol. Bound ribosomes are found on endoplasmic reticulum, which is a membrane in the cytoplasm
What is a codon?
Info written in a code. It is a sequence of three nucleotides that together form a unit of genetic code in a DNA or RNA molecule.
What is an anti-codon?
Codes for codons. It is a sequence of three nucleotides in tRNA.
What molecule contains an anticodon?
tRNA
What are 3 differences between DNA and RNA?
- Location - DNA is found in nucleus. RNA is found in nucleus and cytoplasm.
- Sugar: DNA sugar is deoxyribose. RNA sugar is ribose.
- Bases: DNA bases are A,T,C,G. RNA bases are A,U,C,G
To what does the nitrgenous base Uracil bind?
In RNA, uracil binds with a ribose sugar to form the ribonucleoside uridine. Uracil pairs with adenine through hydrogen bonding.
What are all of the molecules involved in the process of transcription?
(?) mRNA, rRNA, tRNA
What are all of the molecules involved in the process of translation?
(?) mRNA, tRNA, and then a polypeptide (chain of amino acids)
What contribution did Lyell make to evolution?
If the earth is changing perhaps organisms are changing as well
What contribution to Hutton make to evolution?
The earth is more than 6000 yaers old
What contribution did Malthus make to evolution?
Human population has limiting factors
What contribution did Lamarck make to evolution?
organisms adapted to their environments through acquired traits
What contribution did Darwin make to evolution?
everything in evolution changes
Compare and contrast Darwinian evolution to Lamarckian evolution
Darwin: top have less competition
Larmark: perfection with use and need
What contribution did Mendel make to evolution?
He determined that organisms have 2 factors for each trait, but only passed on one to each offspring.
What contribution did Avery make to evolution?
He determined that chromosomes have genetic info
What contribution did Wallace make to evolution?
He discovered principles of evolution and natural selection
What contribution did Hershey Chase make to evolution
He determined that the DNA of a chromosome had genetic info., not proteins
What can be learned from studying fossil records?
Fossils in layers show organisms have populated earth for a long period of time.
What are homologous structures and what do they tell us about the organisms that possess them?
remnants of structures that were function in ancestral species
What are analogous structures and what do they tell us about the organisms that possess them?
separate evolution of structures
Why do vertebrate embryos look similar at early stages of development?
came from common ancestors
What can be learned from comparing the embryos of vertebrates throughout development
different stages of development changes organisms
How does the molecular record compare between closely related organisms and distantly related organisms?
Closely related species have sequences that are more similar than distantly related species
How can artificial selection be used as evidence for natural selection?
breeding can use variations in populations to create vastly different breeds and varieties
Describe how a pathogen can become resistant to antibiotics
inherited resistance to antibiotics from parents
What are the key elements required for natural selection to take place?
1) Organisms have inheritable variation
2) There is always competition for scarce resources. There will be more organisms that can survive.
3) Those best adapted to environment will best survive and pass traits to offspring.
What leads to directional, disruptive, and stabilizing selection?
Directional selection: Individuals with extreme traits are more fit. (Directional selection is a type of natural selection that favors one extreme phenotype over the mean or other extreme.)
Disruptive selection: One population divides itself between 2 niches, so 2 species will arise.
Stabilizing selection: Individuals with average traits are more fit. Eliminates extremes.
What is genetic drift? Say two things about it.
1) Sometimes a mutation causes a new phenotype that neither benefits nor reduces the population fitness.
2) Genetic drift is the effect of chance events
Compare the founder effect and bottleneck event
Founder effect: new population is started by only a few individuals
Bottleneck effects: Some factor (e.g., disaster) reduces population to a small number and the population recovers and expands again.
What is ecology the study of?
The study of the interactions of organisms with each other and their environment.
What is a niche?
How an organism lives in relationship to the other members of its biotic community or ecosystem
What is the difference between biotic and abiotic factors in an ecosystem?
abiotic: non-living; physical rather than biological
biotic: living things
How much energy is able to be transferred from one trophic level to the next?
10%
Why are tropic pyramids usually short?
energy constantly lost
What happens to nutrients in an ecosystem?
nutrients are constantly recycled
What classifies a species as a keystone species?
species that a larger impact on the environment then would be predicted by their population size - apex predators
What are non-native, or invasive, species so dangerous to an ecosystem?
They are not natural predators. Often disrupts the balance in a previously stable environment. Takes over the environment.
What is symbiosis?
A relationship between organisms that live closely together
Compare the 5 main types of symbiosis
competition : -/-
Predation/parasitism: -/+
mutualism: +/+
commensalism: +/o
What is “aposematic” coloration?
Bright warning to predators
