1st Semester 59 - BIOLOGY JUNCTION

Energy in Food Writeup

Energy in Food Write Up

Introduction:

Use your lab and your textbook to locate and include the following information in your introduction.

What organisms are capable of making their own food?
What process do they use to do this?
Where do these organisms get their energy for food-making?
This energy is captured with the help of what pigment?
This energy is stored in what organic molecules?
Where exactly in the organic molecules is the energy stored and so it can be used again later? (Hint: Energized electrons form these and then energy is released again when they are broken.)
What process takes place in plants & animals to release energy?
What gas is required for the process to occur?
When foods are “burned” in our bodies, where is the energy being released from? Where did this energy originally come from?
What is the usable form of energy for our cells?
Define calorimetry and explain how it can be used to measure energy stored in chemical bonds of food.

Hypothesis:

Write a statement explaining that calorimetry can be used to detect the amount of energy stored in the chemical bonds of foods.

Materials:

In sentence form, write a statement listing the materials required for this lab.

Procedure:

In paragraph form, write the procedures for completing this lab.

Results:

Draw and fill in table 1 showing the results of burning
Draw and fill in table 2 showing your data analysis for nut calorimetry
Write out and answer the questions on the lab. Remember to write and underline the question, but do NOT underline the answer.

Conclusion: (Write in paragraph form.)

Restate your hypothesis.
Tell how were you able to measure the amount of energy in each nut
Did all three nuts contain the same amount of food energy? Explain by giving data from your experiment..
Explain why some foods contained more energy than others
Tell where this energy originally come from and how it got into the nuts
Explain any errors you might have made in lab that could have affected your results

DNA Code for Insulin

DNA’s Instructions for Insulin

Introduction:

Below are two partial sequences of DNA bases (shown for only one strand of DNA) Sequence 1 is from a human and sequence 2 is from a cow. In both humans and cows, this sequence is part of a set of instructions for controlling the production of a protein. In this case, the sequence contains the gene to make the protein insulin. Insulin is necessary for the uptake of sugar from the blood. Without insulin, a person cannot use digest sugars the same way others can, and they have a disease called diabetes.

Materials:

paper, pencil, codon table

Procedure:

Using the DNA sequence given in table 1, make a complimentary RNA strand for the human. Write the RNA directly below the DNA strand (remember to substitute U’s for T’s in RNA).
Repeat step 1 for the cow. Write the RNA directly below the DNA strand in table 2.
Use the codon table in your book to determine what amino acids are assembled to make the insulin protein in both the cow and the human. Write your amino acid chain directly below the RNA sequence.

Table 1

Sequence 1 Human
DNA	C C A T A G C A C G T T A C A A C G T G A A G G T A A
RNA
Amino Acids

Table 2

Sequence 1 Cow
DNA	C C G T A G C A T G T T A C A A C G C G A A G G C A C
RNA
Amino Acids

Analysis:

1. The DNA sequence is different for the cow and the human, but the amino acid chain produced by the sequence is almost the same. How can this happen?

2. Diabetes is a disease characterized by the inability to break down sugars. Often a person with diabetes has a defective DNA sequence that codes for the making of the insulin protein. Suppose a person has a mutation in their DNA, and the first triplet for the gene coding for insulin is C C C (instead of C C A). Determine what amino acid the new DNA triplet codes for. Will this person be diabetic?

3. What if the first triplet was C A A ?

4. How is it that a code consisting of only four letters, as in DNA ( A, T, G, C ) can specify all the different parts of an organism and account for all the diversity of organisms on this planet?

DNA sequences are often used to determine relationships between organisms. DNA sequences that code for a particular gene can vary widely. Organisms that are closely related will have sequences that are similar. Below is a list of sequences for a few organisms:

Human	CCA TAG CAC CTA
Pig	CCA TGG AAA CGA
Chimpanzee	CCA TAA CAC CTA
Cricket	CCT AAA GGG ACG

5. Based on the sequences, which two organisms are most closely related?

6. An unknown organism is found in the forest, and the gene is sequenced, and found to be C C A T G G A A T C G A , what kind of animal do you think this is?

DNA Replication Lab

Modeling DNA Replication

Introduction

Within the nucleus of every cell are long strings of DNA, the code that holds all the information needed to make and control every cell within a living organism. DNA, which stands for deoxyribonucleic acid, resembles a long, spiraling ladder. It consists of just a few kinds of atoms: carbon, hydrogen, oxygen, nitrogen, and phosphorus. Combinations of these atoms form the sugar-phosphate backbone of the DNA — the sides of the ladder, in other words.

Other combinations of the atoms form the four bases: thymine (T), adenine (A), cytosine (C), and guanine (G). These bases are the rungs of the DNA ladder. (It takes two bases to form a rung — one for each side of the ladder.) A sugar molecule, a base, and a phosphate molecule group together to make up a nucleotide. Nucleotides are abundant in the cell’s nucleus. Nucleotides are the units which, when linked sugar to phosphate, make up one side of a DNA ladder.

During DNA replication, special enzymes move up along the DNA ladder, unzipping the molecule as it moves along. New nucleotides move in to each side of the unzipped ladder. The bases on these nucleotides are very particular about what they connect to. When the enzyme has passed the end of the DNA, two identical molecules of DNA are left behind. Cytosine (C) will “pair” to guanine (G), and adenine (A) will “pair” to thymine (T). How the bases are arranged in the DNA is what determines the genetic code.

When the enzyme has passed the end of the DNA, two identical molecules of DNA are left behind. Each contains one side of the original DNA and one side made of “new” nucleotides. It is possible that mistakes were made along the way — in other words, that a base pair in one DNA molecule doesn’t match the corresponding pair in the other molecule. On average, one mistake may exist in every billion base pairs. That’s the same as typing out the entire Encyclopedia Britannica five times and typing in a wrong letter only once!

Objectives

The replication of DNA before cell division can be shown using paper templates for the components of DNA nucleotides.

Materials

Cut Outs of basic subunits of DNA
Colors or markers
Scissors
Tape or glue
Paper & pencil

Procedure:

Cut out all of the units needed to make the nucleotides from the handout provided.
Color code the Nitrogenous bases, phosphorus, and deoxyribose sugar as follows —
Adenine = red, Guanine = green, Thymine = yellow, Cytosine = blue, Phosphate = brown, and Deoxyribose = purple.
Using the small squares and stars as guides, line up the bases, phosphates and sugars.
Now glue the appropriate parts together forming nucleotides.
Construct DNA model using the following sequence to form a row from top to bottom – cytosine (topmost), thymine, guanine, and adenine (bottommost).
Let this arrangement represent the left half of your DNA molecule.
Complete the right side of the ladder by adding the complementary bases. You will have to turn them upside down in order to make them fit.
Your finished model should look like a ladder.
To show replication, separate the left side from the right side, leaving a space of about 6-8 inches.
Use the remaining nucleotides to complete the molecule using the left side as the base.
Build a second DNA model by adding new nucleotides to the right half of the original piece of the molecule.
Tape the nucleotides together to form 2 complete DNA ladders.

Questions

1. Of the 4 bases, which other base does adenine most closely resemble?

2. List the 4 different nucleotides.

3. Which 2 molecules of a nucleotide form the sides of a DNA ladder?

4. If 30% of a DNA molecule is Adenine, what percent is Cytosine?

5. What does the term replication mean?

6. What is another name for adenine and three phosphate molecules attached to it?

Effect of Solutions on Cells

Effect of Solutions on Cells

What happens when cells are place in different kinds of solutions

Plant cells placed in a hypertonic solution will undergo plasmolysis, a condition where the plasma membrane pulls away from the cell wall as the cell shrinks. The cell wall is rigid and does not shrink.

The Elodea cells have been placed in a 10% NaCl solution. The contents of the cells have been reduced to the spherical structures shown.

Normal Elodea cells

Animal cells placed in a hypertonic solution will undergo crenation, a condition where the cell shrivels up as it loses water. Red blood cells in a hypotonic solution will swell and burst or lyse.

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Egg Osmosis Sample 1 Lab

Osmosis through the Cell Membrane of an Egg

Introduction:
The cell or plasma membrane is made up of phospholipids and different types of proteins that move laterally. These include peripheral proteins, which are attached to the interior and exterior surface of the cell membrane. Integral proteins are embedded in the lipid bilayer. Attached to these integral proteins are carbohydrate chains. These carbohydrates may hold adjoining cells together, or act as sites where viruses or chemical messengers such as hormones can attach. Cell membranes are selectively permeable. They allow some substances to pass through, but not others. Small molecules that are usually nonpolar, such as oxygen, water, and carbon dioxide, easily move through the lipid bilayer. Larger molecules, such as glucose, the food for all living things, must seek aid from the carrier proteins in a process called facilitated diffusion. Facilitated diffusion is a process used for molecules that cannot diffuse rapidly through cell membranes. Integral proteins are used by calcium, potassium, and sodium ions to move through the cell membrane. The muscles and nerves use these ions.
Diffusion is the movement of molecules from an area of higher concentration to an area of lower concentration. This difference in the concentration of molecules across a space is called a concentration gradient. Diffusion is a type of passive transport, meaning it does not require energy input by the cell. This type of transport and osmosis are the two processes used in this lab. Osmosis is the process by which water molecules diffuse across a cell membrane from an area of higher concentration to an area of lower concentration. When the concentration of the solute is higher outside of the cell, it is known as a hypertonic solution. When the concentration of the solute is lower outside of the cell, it is known as a hypotonic solution.

Hypothesis:
The substance, syrup, which has a higher solute concentration than the interior of the eggs, will cause water to leave the eggs’ membrane; the other substance, distilled water, which has a lower solute concentration than the eggs’ interior, will cause liquid to enter the eggs’ membrane.

Materials:
The materials necessary for this lab are: two fresh eggs in their shells, a felt tip marker, 200mL graduated cylinder, five jars, clear Saran wrap, white vinegar, clear sugar syrup (Karo), distilled water, tap water, pencil, paper, eraser, computer, electronic scale, and a plastic tray.

Methods:
Day One: On day one, label the five jars, with the felt tip marker: one labeled vinegar, two labeled syrup, and two labeled distilled water. Also put the group number on each jar. Find the mass of each egg and record this information in the data table. Place the two eggs in the jar labeled vinegar. Add vinegar until both eggs are submerged by it. Cover the jar with the clear Saran wrap. Place the jar on the plastic tray and allow to set for 24 hours.

Day Two: On day two, observe what has happened to your eggs. Record this in a data table. Now that the eggs’ shells are dissolved, gently remove the eggs from the vinegar. Rinse each egg with tap water. Pat the eggs dry with paper towels and mass them separately on the electronic balance. Record this in the data table. Place the eggs in the jars labeled syrup. Add syrup to each jar (labeled egg 1 or egg 2) until the eggs are submerged in syrup. Loosely cover each jar with Saran wrap. Place the jars on the tray and allow them to soak for 24 hours.

Day Three: On day three, observe what has happened to the eggs and record this information in the data table. Carefully remove the eggs from the syrup and rinse them with tap water. Pat dry with paper towels. Using the electronic balance, find the mass of each egg separately and record these masses in the data table. Place the eggs in the jars labeled distilled water (labeled egg 1 and egg 2). Add distilled water to each jar until the eggs are covered. Cover the jars with the Saran wrap and allow them to sit on the tray for 24 hours.

Day Four: On day four, remove the eggs from the jars and record the eggs’ appearance. Mass each egg on the electronic balance. Record this in the data table. Dispose of the eggs in the container provided by the teacher.

Results:

Egg 1 Data Table

Substance egg submerged in	Egg’s mass before placed in substance	Egg’s mass after removed from substance	Observations of egg before placed in solution	Observations of egg after removed from substance
Vinegar	59.2 g	86.0 g	The egg’s shell is intact and is included in the first mass.	The egg’s shell dissolved and wasn’t included in the 2nd mass.
Syrup	86.0 g	53.2 g	The egg is swollen and soft, yet firm to touch.	The liquid inside the egg diffused into the syrup.
Distilled Water	53.2 g	86.5 g	The egg has lost some of its firmness.	The water diffused into the egg, increasing the egg’s mass.

Egg 2 Data Table

Substance egg submerged in	Egg’s mass before place in substance	Egg’s mass after removed from substance	Observations of egg before placed in solution	Observations of egg after removed from substance
Vinegar	58.8 g	85.6 g	The egg’s shell is intact and is included in the first mass.	The egg’s shell is mostly dissolved and so wasn’t included in 2nd mass.
Syrup	85.6 g	52.2 g	The egg is rough to touch and feels rather sturdy.	The liquid inside the egg diffused into the syrup.
Distilled Water	52.2 g	88.9 g	The egg feels more fragile and lighter in weight.	The water diffused into the egg increasing the egg’s mass.

Egg in Hypotonic Solution of Vinegar & Plasmolyzed Egg in Distilled Water	Egg in Hypertonic Solution of Syrup

1. When the egg was place in the water, in which direction did the water molecules move? The water moved into the eggs from the surrounding environment.

2. On what evidence do you base this? The eggs’ masses had increased from the time they were placed in the water to when the eggs were removed.

3. How do you explain the volume of liquid remaining when the egg was removed from the syrup? The volume of the liquid remaining when the egg was removed from the syrup must have increased because the eggs’ masses had decreased. The liquid within the eggs left the eggs and diffused into the surrounding syrup.

4. When the egg was place in the water after being removed from the syrup, in which direction did the water move? The water moved into the eggs.

Error Analysis:
Several errors may have occurred during this lab. When finding the eggs’ masses, on each occasion, an error may have occurred. Mistakes may have been made when recording these masses on the data table. Some of the eggs’ shell may have been left on the eggs’ membranes and changed the outcome of this lab. When the eggs were rinsed, after being placed in the vinegar and syrup, a small amount of water could have entered through the membranes of the eggs, effecting their masses. These are just a few of the errors that may have taken place throughout the lab.

Discussion and Conclusion:
The hypothesis was correct. When the eggs were placed in the syrup, their masses decreased greatly. This shows that the interior of the eggs must have had a lower solute concentration than their surrounding environment of syrup. The water within the eggs left through the membrane and diffused into the syrup, decreasing its solute concentration. When the eggs were placed in the distilled water, their masses greatly increased. This shows that the interior of the eggs must have had a higher solute concentration than their surrounding environment of distilled water. The distilled water diffused into the eggs’ membrane, decreasing the interior of the eggs’ solute concentration.

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