Practical Exam
How many homologous chromosomes do humans have? (autosomes)
22
Plasma contains how much water and how much dissolved salts and proteins?
90% water 10% dissolved salts and proteins
What is the equation for the relationship between absorbance and transmittance?
A=log(1/T)
What is the effect of acid and bases on dh2o?
Acids: PH decreases as more drops are added Bases:PH increases as more drops are added
What is the difference between adsorption and absorption?
Adsorption: is the adhesion of molecules of gas, liquid, or dissolved solids to a surface (creates a film). Absorption: a fluid permeates or is dissolved by a liquid or solid
Isotonic
Amounts of solute inside=amount in environment
Briefly describe how PH affects an enzyme's activity?
As PH become more neutral, enzyme activity speeds up and as PH becomes more basic of acidic, enzyme activity slows down
What color does a buiret reagent turn a solution, and what color does a protein form?
BR: Pink Protein: Purple
What color is a biuret reagent?
Blue
Explain the difference between chromosome, chromatid, and chromatin?
Chromatin is the DNA before it coils. Chromosomes are the coiled DNA
Guaiacol is ___________ in its reduced state and turns _____________ as it is oxidized
Colorless, Brown
What occurs in the "S" phase of the cell cycle?
DNA replication
nucleic acids
DNA, RNA
Dialysis
Diffusion of a solute
Acids
Donate free H+
Bases
Donate free OH- or accept a free H+
What role does HCL play in the digestive process and how might antacid use affect this process? ****
HCl is highly acidic, so an antacid might not let HCl break down minerals.
Hypertonic
High solute in environment so cell shrinks
Hypotonic
Huge swelling, concentration of solute high
If the PH of a solution changes from PH 8 to PH 5, the [h+] has (increased/decreased) by a factor of ______________.
Increased, 1000
What des peroxidase do?
It breaks down Hydrogen peroxide into water and oxygen
How does PH effect the activity of peroxidase?
It is most stable between 6 and 7 and when the PH raises the absorbance decreases and as it lowers it decreases as well.
What is the substrate?
It undergoes the reaction
Describe two key differences between mitosis and meiosis?
Meiosis: sexual Mitosis: Asexual Meiosis: crossing over occurs Mitosis: crossing over does not occur Meiosis: 2 divisions mitosis: 1 division
Equation to calculate PH
PH=-log[H+]
Osmosis and Dialysis are active or passive?
Passive
What is the biuret reaction specific for?
Proteins and small peptides
Rf equation
Rf=distance travelled by component, cm/ distance travelled by solvent,cm
carbohydrates
Sugars, starch, cellulose, glycogen
Osmosis
The diffusion of water across a semipermeable cell membrane
What happens to an enzyme when it is boiled?
The enzyme reaction stays constant, so the enzyme stops working
How does varying the amount of enzyme affect the rate of the reaction for peroxidase?
The more the enzyme, the more absorbance
How does varying the amount of substrate affect the rate of the reaction for peroxidase?
The more the substrate, the more absorbance
How does temperature affect the activity of the enzyme, peroxidase?
The optimal temperature is 45 degrees Celsius. At 100 degrees the activity remains constant and wen temperature decreases from 45 the activity decreases. When the temp increases from 45 the activity decreases.
Diffusion
The random movement of molecules in response to a concentration gradient
What is meant by "optimal" temperature for an enzyme reaction?
The temperature at which the most absorption takes place.
What is lambda max?
The wavelength where the substance absorbs most strongly
How do enzymes catalyze?
They speed up the rate of a chemical reaction by lowering the activation energy, but are not consumed by the reaction
What happens in the active site?
This is where the reaction takes place
What is a Spectrophotometer used for?
To detect and measure the amount of light absorption at a specific wavelength.
What does the absorption spectrum help identify?
a wavelength that would be most useful for detecting the substance based upon its absorption maximum (lambda max)
What does PH refer to?
acidic, neutral, or alkaline (basic) nature of a solution
List three things that you think would be important criteria for an affective antacid?
buffer non-acidic basic
Name two molecular characteristics of amino acids?
can be hydrophilic; can be hydrophobic
Name the 7 funcitonal groups
carrie had a stuffed animal kangaroo pet carboxyl hydroxyl aldehyde sulfydryl amino ketone phosphate
Eukaryotic
cells of plants, animals, and fungi have true membrane enclosed nucleus
Tonicity
effects of osmosis on living cells
Lipids
fats, phospholipids, steroids
Why do amino acids travel different distances?
hydrophobicity;polarity;acidity/basidity
Prokaryotic
lack membrane-bound organelles
how can you calculate PH if you are given [OH-]?
pOH=-log[OH-] and pH+pOH=14
Buffer
prevent dramatic PH shifts in solutions
What is a blank?
provides background reading; tells you what solution looks like without substance of interest
Chromatography
separates and identifies the various amino acids
Rate of Reaction Equation
slope= deltaA/min
Plasmolysis refers to the __________ in plant cells
swelling of a cell membrane
Enzyme function is dependent on what 4 environmental factors?
temperature, PH, substrate concentration, and salt concentration
what is a karyotype?
the number and visual appearance of the chromosomes in the cell nuclei of an organism or species.
A solutions color and intensity are dependent on what?
the type and amount of protein present
In protein synthesis the process of ___________ converts DNA to mRNA and the process of _________ converts mRNA into a polypeptide
transcription, translation
