Wednesday, May 28, 2014

Dissection Lab


Grasshopper Dissection Video

The heart is separated into different ventricles, valves and atria to pump blood through the body of the grasshopper

A pouch in many birds and some lower animals that resembles a stomach for storage and preliminary maceration of food

Gastric Caecae
The gastric caecae are long fingery glands next to the gizzard and the stomach of a grasshopper that secrete enzymes that aid in digestion

It absorbs water and compacts waste. It also Transports waste from the stomach to the rectum.


Frog Dissection Video

Vomerine/maxillary teeth- teeth for holding prey

Tongue- attached in front. Brings food to the back of the mouth

Glottis- opening in back if the mouth. Leads to trachea then the lungs

Gullet- large opening in back of mouth. Leads to the stomach

Esophagus- tube like structure from mouth to stomach

Stomach- breaks down food

Small intestine- more digestion and absorption of nutrients

Liver- produces bile to break down fats, store glucose, and detoxify

Gallbladder- stores bile

Cloaca- an opening on the outside of the body that waste and reproductive cells pass through as they exit the body

Pancreas- produces hormones and digestive enzymes

Large intestine- reabsorbing of water into the bloodstream

Spleen- stores, produces and removes RBC's from blood

Oviducts-transports eggs to the cloaca

Fat bodies- stores fat used in metamorphosis of hibernation

Kidney- filters waste and toxins from the blood

Urinary bladder- stores liquid waste from the kidney

Lung- allows exchange of oxygen and carbon dioxide

Ventricle- lower pumping chamber of the heart

Atrium- upper receiving chamber of the heart

Bone- support

Eggs- female reproductive gametes

Testes- male reproductive gonads


Earthworm Dissection Video

Muscular apparatus to suck up food that is in soil

Food is forced from the crop, and grains of sand grind up the food in the digestive system

Seminal receptacles
Stores sperm from another worm

Seminal vesicles
Extend from the testis sacs and stores sperm produced by two pairs of testes within the sacs

Thin wall organ that acts as a temporary storage place for food

5 aortic arches that connect the dorsal and ventral blood vessels to pump blood through the body of the worm

Muscular pharynx used to feed

Metameres (segments)
Rings on the outer part of the worm that individualize parts of the worm so the worm can still function as normal if a segment is damaged

Located on the opposite end of the worm from the mouth, it's a small opening of the intestines to release waste

Dorsal Blood Vessel
Tube that extends the length of the body. It is contractile and pushes blood forward in the earthworm and is pumped into the aortic arches

Ventral Blood Vessel
Tube that extends the length of the body. It pumps blood away from the heart towards the posterior end

Extends from stomach as the digestive track where the enzymes break down the food and the blood of the intestine wall absorbs the nutrients


Starfish Dissection Video

Function: Claw type structures that are thought to help in the cleanliness of the star fish 

Function: Filter water into the water vascular system 

Digestive Glands 
Function: Break down food 

Function: Protection, especially tube feet, and the spinal nerves 

Tube Feet
Function: Used for feeding, movement, and respiration 

Pyloric Stomach 
Function: Breaks down food with the help of enzymes 

Cardiac Stomach
Function: Comes put of the mouth to digest nutrients 

Function: Used in reproduction 

Function: Fill with water and force into tube feet to create movement 

Ambulacral Plates 
Function: Contains the tube feet and is used to pry open shells 

Ring Canal
Function: Carries water from the stone canal to the radial canal

Radial Canal
Function: Takes water out to the arms from the ring canal towards the ampullae 


Perch Dissection Video

Organ used for oxygen exchange with the water

It absorbs nutrients from waste.

Filters waste from blood

Excretes digestive enzymes and other digestive functions.

Produces and stores red blood cells.

Pumps blood to different parts of the fish.

Swim or air bladder
Closed sac that secretes and absorbs oxygen that maintains the fish at a pressure level.

Food is digested and processed.

Thursday, March 20, 2014

pGlo Lab

At first, we took two micro test tubes and labeled them as containing the plasmid pGLO (+pGLO) and not containing it (-pGLO). We then transferred 250 microlitres of calcium chloride (CaCl2) into the tube. This is used as a transformation solution to help the e. Coli absorb the plasmid and give the desired effects. After placing the tubes on ice, we then transferred some bacteria from the starter plate to the tubes. We then took plasmid DNA containing the pGLO and placed it into the +pGLO tubes. After placing the tubes on ice again for 10 minutes, we placed the tubes in a hot water bath at 42 degrees Celcuis for 50 seconds, then immediately moved them back to the ice for 2 minutes. We then transferred 250 microlitres of LB nutrient broth to the tubes and incubated them for 10 minutes. We then put 100 microlitres of transformation and control suspension onto the plates. We then spread the solution around the plates, closed them up and incubated at 37 degrees celcius until the next day. Then we counted the colonies on each plate and held a uv light to the plate with arabinose to see if it glowed. 

The purpose of the experiment was to genetically alter bacteria. We wanted to see if we could move the genes from the jellyfish plasmids to the e. Coli. The concept we were testing was called genetic transformation. The dependent variables were whether or not we added pGLO and what ager we put the solution on. The relationship was that if there was pGLO and the ager had arabinose and ampicillin then the E. coli glowed and was antibiotic resistant. If there was pGLO but no arabinose then it didn't glow but was still antibiotic resistant. If there wasn't pGLO and there was ampicillin, then all the bacteria died. If there wasn't ampicillin ethn the bacteria svurived. We were really trying to if we could alter the plasmid to meet our needs through genetic transformation. 

Genetic transformation is inserting a gene into an organism to change that organisms traits. In this lab the bacteria E. coli will be altered with genes that code for florecence and for ampicillin resistance. Ampicillin is an antibiotic.  The gene for florecence came from a jellyfish and will cause the bacteria to glow green under the uv light. The "glow" gene is switched on by the presence of a sugar, arabinose, in the ager that the bacteria is put on. The bacteria that was transformed will appear on plates with LB/amp and will glow on plates with arabinose. 

Transformation efficiency is calculated by the total number of cells growing on the agar plate divided by the amount of DNA spread on the plate (in micrograms). The number of cells on the agar plate can be calculated by the amount of colonies, all of which most likely originated one cell. To find the amount of DNA spread on the plate, the number of transformants is divided by the concentration. Our transformation efficiency was 191.251 transformants per microgram. This is much lower than the average 700-800 transform ants per microgram. This lower efficiency was probably caused by a human error. For the -pGLO lb/amp there was no growth, which is what was to be expected as it didn't have the ampicillin resistance. The only plate that glowed was the LB/AMP/ARA because it had the arabinose to fuel the glowing. Any cause for an odd result could've been cross contamination. Even though many precautions were taken against it, like using sterile loops and disposalbe pipettes, but there is a chance that something could've contaminated it while we put it on the table. However, the results that we got do support what we thought the outcome the outcome would've been. Any plate with +pGLO was expected to survive. Any plate that didn't have pGLO could only survive on a plate without ampicillin. 

The lab

We did, in fact, alter the bacteria with the plasmids through genetic transformation. We know that the bacteria was altered because there was growth on the ampicillin plate and it glowed on the plates with arabinose. If the transformation didn't work then all the bacteria on the ampicillin plate would've died and there would've been no glowing bacteria. 
For the +pGLO LB/amp plate, a little growth was seen. This means that some of the cells accepted the plasmid and prevented the ampicillin from killing the bacteria. 

Sunday, January 12, 2014

Photosynthesis Lab

Purpose(lab 1): to use chromatography to separate the photosynthetic pigments found in spinach

Introduction(lab 1): chromatography is a technique for separating materials. Some pigment is smeared near the bottom of the chromatography paper and when the bottom is dipped in a solution, it travels up the paper, taking the pigments with it. Over time the pigments end up spread out along the paper because they traveled up with the solution.

Methods(lab 1):for this lab we smeared spinach at the bottom of the chromatography paper and then dipped the bottom of that chromatography paper solvent. This caused the pigments in the spinach to travel up the paper with the solvent. We then measured to see what pigment was most plentiful in the spinach.
Data(lab 1):

Graphs and charts(lab 1):

Discussion(lab 1):
Paper chromatography separates pigments by dissolving them in a solvent that moves up a strip of paper by capillary action. Different pigments travel different distances up the paper because of their varying solubility and attraction to the paper. For example, beta carotene is more soluble and less attracted to the paper and will be carried further than less soluble, more attractive pigments like xanthophyll. The distance traveled by the pigments is called Rf. Each pigment has its own Rf. It can be calculated by dividing the distance the pigment moved by the distant the solvent front moved. The orange pigment that went the farthest is called Carotene. The green that went the least is called chlorophyll b. this means that carotene is the most soluble and that chlorophyll b is the least.

Conclusion(lab 1): orange traveled the farthest at 11 cm and green traveled the least at 1.7 cm. that means that the most plentiful pigment was carotene and the least plentiful was chlorophyll b. our results are fairly accurate. The only way the data would be wrong is if we read the measurements wrong on the ruler.

References(lab 1): the lab

Purpose(lab 2):the purpose was to see the effects of light changes and boiling the chloroplasts on photosynthesis using DPIP. The independent variable was whether or not the chloroplasts were boiled and the amount of time it spent in the light. The dependent variable was the percent transmittance. The control was the group with no DPIP and the group with no chloroplasts.
Introduction(lab 2): photosynthesis is the process that turns light into sugar. The first half requires light to work. The light energy is absorbed by the chlorophyll which initiates the reactions. When the light is diminished or taken away, the process slows down. After the light is absorbed it goes into the chloroplast. If the chloroplasts are boiled, the proteins would be denatured, and thus wouldn't work.

Methods(lab 2):In this lab we used a colorimeter to see the photosynthetic pigments and how they were different between each other after 5, 10, and fifteen minutes. We used DPIP to activate the reaction and we went to see the breaking down of pigmentation in the spinach. We used a beaker of water to block the heat coming from the flood light, and to keep the dark chloroplasts in the dark we used aluminum foil to cover the tube to avoid contact with light to see how that would affect the reaction.

Data(lab 2):

Graphs and charts(lab 2):

Discussion(lab 2):
All of our data seems wrong for this lab. We think what we were using the colorimeter wrong. It's also possible that our timing was wrong.
for this lab the first cuvette had no DPIP which was the replacement electron carrier. This made it the control. DPIP replaces NADP+ which when reduced completes the light reactions for photosynthesis. This cuvette should've had the lowest percent transmittance because of the lack of DPIP, but me must've screwed up as this cuvette has the highest in our results. The second cuvette had unboiled chloroplasts in the dark. The absence of light makes it so electrons can't travel through photosystem II. this should've caused a lower %transmittance, but our data didn't support this. We think that's because of the reasons at the beginning of the discussion. Cuvette 3 had unboiled chloroplasts in the light. This means that the chloroplasts could go through photosynthesis normally. There was nothing hindering it. The photons from the light would carry the electrons all the way through the process. Cuvette 4 had boiled chloroplasts in the light. The act of boiling them denatured them. That means that they can't go through the act of photosynthesis. Essentially, the chloroplasts were broken. This should've caused a really low percent transmittance like the first cuvette, but like the first cuvette, out data doesn't support it. In the 5th cuvette, there were no chloroplasts. This would cause absolutely no photosynthesis.

Conclusion(lab 2): this lab had the highest absorption In run 2 (unboiled chloroplasts light) and the lowest in run 3 (boiled chloroplasts light). Our data actually shows the highest reading in the first minute of run 4 but this must be a mistake because that run had no chloroplasts in it. Run 3 was the lowest because the chloroplasts were boiled which rendered them useless. Run 2 worked the best because nothing was altered. Our results don't seem correct, though. It's possible that we took the readings wrong or we interpreted the data wrong.

References(lab 2): the lab

Purpose(lab 3): the purpose of this lab was to see if we could improve on lab 2 by making the absorption higher and by making the percent transmittance lower.

Introduction(lab 3): this lab is the same as lab 2 except we used half the dpip (an electron carrier that replaces NADP+)

Methods(lab 3):We used the same procedure, and methods as part 2 but changed one area,we chose to change the amount of dpip going into the procedure. We ended up speeding up the reaction, when in fact we wanted to take away dpip, leading us to slow down the reaction. 

Data(lab 3):

Graphs and charts(lab 3):

Discussion(lab 3):we thought that halving the DPIP would improve our results in the experiment, but it was actually the opposite of what we wanted to do. We should've doubled the DPIP. with the extra DPIP, more electrons would've been able to make their way through, thus improving our results

Conclusion(lab 3): our modification to the experiment didn't work. We got more absorption with less percent transmittance. Except in run 2 where the absorption was higher at first, but was lower in the rest of the measurements than the original lab. This is because the DPIP was used up faster since there was less of it. 

References(lab 3): the lab