Lab Exam 1 (Labs 1-7)

What part of the microscope is this?

ocular lenses (eyepiece)

function of ocular lenses?

eye pieces used to view the magnified image from the slide

What part of the microscope is this?

Body Tube

Function of body tube?

Connects the eyepiece to the revolving nosepiece and objective lenses

What part of the microscope is this?

Nosepiece

function of nosepiece?

supports and lets you switch objective lenses

What part of the microscope is this?

Objective lenses

Function of objective lenses?

Magnifies the image (4x, 10x, 40x, 100x)

name of 4x objective lens

scanning lens

name of 10x objective lens

low power lens

name of 40x objective lens

high-dry power lens

name of 100x objective lens

oil immersion lens

What part of the microscope is this?

Stage Clips

Function of stage clips?

hold the slide in place on the stage

What part of the microscope is this?

Stage

Function of stage?

Supports the slide

What part of the microscope is this?

Diaphragm

Function of diaphragm

controls the amount of light

What part of the microscope is this?

Illuminator

Function of illuminator

light source

What part of the microscope is this?

Arm

function of arm

Supports the tube and connects it to the base; how you carry the microscope

What part of the microscope is this?

Coarse Focus

function of coarse focus knob

Moves the stage up and down for focusing

What part of the microscope is this?

Fine Focus

function of fine focus knob

To precisely focus the image

What part of the microscope is this?

Base

function of base

Bottom of microscope that supports and is held when carrying the microscope

What are the monomers of Carbohydrates?

Monosaccharides (simple sugars)
Glucose, Fructose, Galactose

What are the dimers of carbohydrates?

Disaccharides
Maltose, sucrose

What are the polymers of carbohydrates?

polysaccharides; long chains of single sugars
Glycogen, Starch, Cellulose

What are the monomers of proteins?

amino acids (AA)

What are the dimers of proteins?

AA-AA

What are the polymers of proteins?

polypeptide, peptide, protein

What are the monomers of lipids?

fatty acids, glycerol

what are the dimers of lipids?

none

what are the polymers of lipids?

triglycerides

What was the benedict's test used for?

used to detect the presence of a reducing sugar (simple sugar) in solution

What was a positive result in the benedict's test?

When the initial mixture was heated and there was a presence of reducing sugars, the solution may turn green, yellow, orange, or red depending on the amount of sugar present

what was a negative result in the benedict's test?

When the initial mixture was heated and there was no presence of reducing sugars, the solution will remain blue

What was the Lugol's test used for?

used to detect the presence of different polysaccharides; we used it to test for Strach

What was a negative result in the Lugol's test?

The solution was a color of yellowish/amber
Ex: Cellulose, monosaccharides, and disaccharides \= no color change (Yellowish/amber)

What was a positive result in the Lugol's test?

The solution will have a color change
- starch \= blue/black
- glycogen \= red/brown
- erythrodextrin \= red

What was the Hydrolysis of Starch used for?

used to test the progress of starch digestion (starch hydrolysis) by using the lugol’s test and benedict’s test

* lugol’s test is used to observe the transition of starch to monosaccharides through different color changes
* benedict’s test is used to test for the presence of glucose and maltose at the end of starch hydrolysis

What was the Grease Spot test used for?

used to test for fats by rubbing solution or dropping a drop of solution on paper towel and observing the grease spot

What result indicated a positive (presence of fat)

If a fat or oil is present, then a translucent spot will form on the paper towel

What result indicated a negative (no presence of fat)

If a fat or oil is not present, then it will first have a wet spot but will soon dry

What was the Emulsion Formation test used for?

This test is done to see if the fats/oils present are good to be digested and absorbed, it is beneficial for large droplets of fats/oils to be separated into smaller droplets that can be more readily mix with water

what is an emulsion?

The condition when one liquid is suspended in another liquid

What was a positive result in the emulsion formation test?

If an emulsion has formed, small droplets of oil should be suspended in the water

what was a negative result in the emulsion formation test?

If an emulsion has not formed, there will not be a separation between the oil and water

what was the solubility of fat test used for?

Was used to test if vegetable oil was soluble in a solution or not
- water soluble compounds are polar and usually contain charged functional groups.
- Lipids and fats are non-polar compounds and are not water soluble.
- If you add non-polar compounds to other non-polar solvents they dissolve

what was a positive result in the solubility of fat test?

If the oil is soluble in the solvent, then it will appear to dissolve in the liquid

what was a negative result in the solubility of fat test?

If the oil is not soluble in the solvent, then it will form a separate layer on top of the solvent

what was the Biuret test used for?

used for testing protein and detecting the presence of peptide bonds (2 or more)

what is a positive result in the Biuret test?

A positive will cause a color change to a pink/violet color if there are more than 2 peptide bonds present
- a copper (II) ion is reduced to copper (I), which forms a complex with the nitrogen and carbons of the peptide bonds in an alkaline solution. A violet color indicates the presence of proteins

what is a negative result in the Biuret test?

A negative will not cause a color change and will stay a blue color meaning no peptide bonds were present

what is the ninhydren test used for?

is used to detect amino groups that are free or bound
- ninhydrin reacts with free amino groups to produce ammonia

what is a positive result in the ninhydren test?

If ninhydrin reacts with free amines, a positive result will cause a color change to a deep blue or purple color known as Ruhemann's purple develops.

what is a negative result in the ninhydren test?

A negative result will not cause a color change and the solution will stay clear/a little cloudy.

What does transmittance mean in terms of a spectrophotometer?

Transmittance (T) is the percentage of light that goes through the sample

What does absorbance mean in terms of a spectrophotometer?

Absorbance (Abs) represents the amount of light absorbed by the sample
- a ratio between the amount of light that goes into the solution and the amount of light that leaves the solution

What was the effect of heating the chicken liver?

heating the chicken liver cause, it to denature, meaning that the condition/environment of the liver changed. By having a different condition, now the chicken liver had a different reaction to the hydrogen peroxide than when it was not boiled/heated
- cannot reverse this condition

what was the effect of acid to the raw chicken liver?

With the raw liver there was an immediate reaction, the liver turned a cloudy yellow with a bunch of bubbles.

What is osmosis?

diffusion of water across a semipermeable membrane
- the semipermeable membrane is necessary for osmosis because it restricts the movement of certain solutes. allowing the solvent to pass through

What is net osmosis?

always results in a net movement of water molecules from a region of high water concentration to a region of low water concentration

what is osmotic pressure?

the concentration of dissolved particles
- the greater the osmotic pressure, the greater the rate of diffusion

what is Brownian movement?

all molecules are in constant motion and collide with other molecules
- this random movement is called this, and it accounts for the process of diffusion

what is diffusion?

The movement of molecules from an area of high concentration to an area of low concentration by random molecular motion

what is net diffusion?

eventually results in a uniform distribution of the solute molecules

what is filtration?

the passage of materials through a membrane by a physical force such as gravity or pressure

What does isotonic mean?

means that the cell's environment (outside of cell) has a NaCl concentration equal to the NaCl concentration that the cell has (inside of cell).
- The cell's environment (outside) has a NaCl concentration equal to 0.85%.
- If cells were placed in an isotonic solution, the water movement in and out of the cell would be equal

what does hypertonic mean?

means that the cell's environment (outside) contains a higher concentration of NaCl than the cell itself has (inside).
- In other words, the cell's environment (outside) has a NaCl concentration greater than 0.85%.
- If cells are placed in this type of solution, there will be a net movement of water (osmosis) out of the cell which will cause the cell to crenate or shrink

what does hypotonic mean?

means that the cell's environment (outside) contains a lower
concentration of NaCl than the cell itself has (inside).
- In other words, the cell's NaCl environment (outside) has a NaCl concentration less than 0.85%.
- If cells were placed in this type of solution, water would go into the cell which could cause the cell to swell up and burst.

Understand what was occurring in the sheep blood cell experiment with different concentrations of salt and water

(1) Tube 1 was showing hypertonic, and the cells were shrunken. Meaning the water moved out of the cell, the NaCl concentration was greater on the outside but had a lower water concentration environment so it went there.
(2) Tube 2 was showing isotonic. Both environments had the equal amount of NaCl, so the water moved equally in and out of the cell.
(3) Tube 3 was showing hypotonic, and the cells had exploded. This meant that the NaCl concentration was lower in the environment

what was happening and why in the osmosis race experiment?

Rule \#1 - the greater the concentration differences, the faster the rate of diffusion
- The 60% sucrose solution was traveling much faster in height compared to the 20% solution. It decreased overtime because there wasn't much concentration difference left for more osmosis to occur

what are the rules of diffusion?

(1) the greater the concentration difference, the faster the rate of diffusion
(2) the higher the temperature, the greater the rate of diffusion
(3) the lighter the molecule, the greater the rate of diffusion
(4) the faster molecules move (temperature), the greater the rate of diffusion

which experiments demonstrated rule \#1 of diffusion: the greater the concentration difference, the faster the rate of diffusion

(1) the diffusion if a gas in a gas (demo) - sprayed Febreze and saw the rate of diffusion was faster at first but when the molecules spread out more, the rate slowed down
(2) the osmosis race - the driving force decreased over time, since the concentration got lower (concentration of sucrose was high \= higher driving force, and then the concentration got lower)

which experiment demonstrated rule \#3 of diffusion: the lighter the molecule, the greater the rate of diffusion

the diffusion of a solid through agar: we saw that the lighter molecule diffusion faster than the heavier molecule
- potassium permanganate is 158 g/mol - faster rate (spread out more after a certain amount of time)
- methyl orange is 327 g/mol - slower rate (spread out less after a certain amount of time)

which experiment demonstrated rule \#2 of diffusion: the higher the temperature, the greater the rate of diffusion

the diffusion of a solid through a liquid - demo
- we saw that the potassium permanganate diffusion immediately after being put in a warm solution compared to a cold and room temperature solution

What is presbyopia?

changes in vision with age due to less flexible lens
- loss of elasticity

What is astigmatism?

Defect in cornea or lens that causes an uneven bending of the light rays in that area of the eye
- blurred vision due to the misshape cornea on lens
- corrected by glasses or special contact lenses

what is myopia?

nearsightedness, have trouble seeing objects at a distance
- eyeball too long

what is hyperopia?

farsightedness (can't see close up)
- eyeball is too short

what is emmetropia?

normal vision: eyeball is a normal shape

what is nystagmus?

involuntary continual movement of the eyes as if to adject to constant motion

what happens during the Babinski reflex?

the lateral aspect of the sole of the relaxed foot is stroked:
- a negative result means that the toes curl (normal)
- a positive result means that the toes fan out (Babinski reflex is present - normal for infants under the age of 6 months)

How can nystagmus be induced?

The semicircular canals can be stimulated by rotating a subject in a chair (to stimulate the horizontal canal the head must be flexed 30° forward).
- When the subject is first rotated to the right, the cupula will be bent to the left because of the inertial lag of the endolymph.
- This will cause nystagmus in which the eyes drift slowly to the left followed by a quick movement to the right.

what happens during the pupillary reflex?

a light is shined on the eyes, which should cause the pupils to constrict in response to the light
- adjusting the amount of light that reaches the retina

what happens in the consensual reflex?

One eye is going to get shined by a light while the other eye will not get any light
- Both pupils will constrict even if only one eye is receiving light because both optic nerves are activated together since they are innervated by the same neuron

what happens in the ciliospinal reflex?

this reflex has to do with our flight or fight respond
- our pupils will dilate in response to noxious stimuli, such as pinching to the face, neck, or upper trunk
- will dilate to get more information

how can reaction times be measured?

(1) dropping a meter stick and seeing at what point the person grab the meter stick
(2) using an automatic reaction timer and asking the person to step on the footpad on the floor when he sees the red light or hears the sound (tests eyesight and hearing)

what are the components of a reflex?

1. stimulus
2. receptor (Strech receptor)
3. sensory neuron (afferent neuron)
4. interneuron (spinal cord)
5. motor neuron (efferent neuron)
6. effector (muscle)
8. response

What is transduction?

the conversion process where receptors located at the ends of afferent neurons detect changes, or stimuli, and convert these stimuli into electrical energy, or action potentials, that can be transmitted to the CNS

what are modalities?

Heat, light, pressure, chemical changes, and sound are all types of this (stimulus energy)

what is adequate stimulus?

the type of stimulus to which each type of receptor responds best to

What is the law of specific nerve energies?

when receptors will always give rise to the same sensation no matter how they are stimulated

what are photoreceptors?

This is a type of receptor that are responsive to light.
- found only in the eyes

What are mechanoreceptors?

This is a type of receptor that are sensitive to mechanical energy
- ex: skeletal muscles receptor \= to stretch
- receptors in ear \= fine hair cells bend as a result of fluid waves

What are thermoreceptors?

This is a type of receptor that are sensitive to heat and cold