Oh Deer!

Desity-dependent and Density-independent Factors

Many factors affect the ability of wildlife to survive over time. Weather conditions, disease, predators, pollution and habitat destruction are some examples. Habitat is the key to wildlife survival and population size.

For the purposes of this exercise, habitat is defined as food, shelter and water. If any one of them is lacking or restricted in availability then wildlife numbers are reduced. In the accompanying exercise, students learned that organism numbers will be governed by the availability of habitat elements.

The class was divided into two groups of deers and resources.  Each round the deers decided whether they are hungry, thirsty or cold so they could make the related symbols.  The other team of students decides whether they are food, water or shelter (Destity-independent factors) and they make the same symbols. The deer then ran across the space and caught their food, water or shelter. Only one deer per person. If there were more deer that need water than there were ponds, then the deer died and stayed on the side of the necessities. The deer that got what they need, reproduced and took their new deer with them back to the deer's team. After each round an equlibrium was reached between the resources and the population of the deers.  After a while, deer population was hit by Density-dependent factors such as forest fore, drought and predators.  These factors could actualy lead the population of deers to an extinction while density-independent factors led the population to an equlibrium. 



Photosynthesis and Cellular Respiration

Kerb Cycle

Kerb Cycle

The Krebs cycle refers to a complex series of chemical reactions that produce carbon dioxide and ATP. The cycle occurs by essentially linking two carbon coenzyme with carbon compounds; the created compound then goes through a series of changes that produce energy. This cycle occurs in all cells that utilize oxygen as part of their respiration process. Carbon dioxide is important for various reasons, the main one being that it stimulates breathing, while ATP provides cells with the energy required for the synthesis of proteins from amino acids and the replication of DNA; both are vital for energy supply and for life to continue. In short, the Krebs cycle constitutes the discovery of the major source of energy in all living organisms. 



Metabolism + 3 laws of Thermodynamics

1-First Law of Thermodynamics: Energy can be changed from one form to another, but it cannot be created or destroyed.  The Total amount of energy and matter in the universe remains CONSTANT from one form to another
With respect to metabolism and the human body, when we say calories are being "burned" it does not mean that the calories are disappearing.  We know that since calories are unites of energy they cannot disappear, they are just being transformed from the chemical form stored whithin your body to either heat or mechanical form that is not stored whithin your body.

2-Second Law of Thermodynamics: states that "in all energy exchange, if no energy enters or leaves the system, the potential energy of the state will always be less than that of the initial state."
This is also reffered to as ENTROPY.

It is important to understand that it is the second law that drives chemical reactions.  The second law tells us whether a metabolic reaction will occur and what the relative distributions of the forms of the energy will be. To predict the tendency of the reaction to occur, we must employ the second law that says the entropy must increase. Thus living systems are not in equilibrium, but instead are dissipative systems that maintain their state of high complexity by causing a larger increase in the entropy of their environments. The metabolism of a cell achieves this by coupling the spontaneous processes of catabolism to the non-spontaneous processes of anabolism. In thermodynamic terms, metabolism maintains order by creating disorder.

3-Third Law of Thermodynamics: or Absolute Zero (-273C) explains that nothing in this temperature can have function because all the thermal kinetic energy ceases.
There would be no function in this temperature and no metabolism takes place because there would be no molecular motion.  Enzymes also cannot function in extremely high or low temperatures.

Carbohydrates



Biotechnological Tools and Techniques



Protein Synthesis Chart

5 Famous Geneticists



Gregor Mendel (19th Century)



Gregor Mendel:

• He was born on July 22, 1822, to a family of poor peasants.
• He became a priest in the year 1847.
• Mendel Studied the inheritance of seven pairs of traits in garden pea plants and in their seeds.
• He bred and crossbred thousands of plants and observed the characteristics of each successive generation.
• Mendel found out that each plant receives a pair of genes for one trait; that is one gene from each of its parents.
• He came to the conclusion that the pairs of genes separated randomly when a plant’s gametes were formed.
• Mendelism and the two laws:

1. Law of Segregation: A parent plant hands down only one gene of each pair to its offspring.
2. Law of Independent Assortment: a plant inherits each of its traits independent of other traits.





Rosalind Franklin (1920-1958)

 
Rosalind Franklin:

• She is best known for her work on DNA and her crucial contributions to the solution of the structure of DNA.
• Using X-ray, she was able to take a picture of DNA and that's how scientists discovered the helical shape of this vital molecule.
• After her death, her unpublished hypothesis that TMV RNA is a single-strand helix was confirmed.

James Watson and Francis Crick

James Watson and Francis Crick:

• With the help of Muarice Wilkins and Franklin's photo of DNA; Watson and Crick determined the structure of DNA and won the Noble Prize this discovery.
• They discovered that DNA is a double-helical molecule – a helical structure with two DNA strands.

• This discovery suggested two important facts about genetic inheritance:

1. Genetic information was carried by the sequence of nucleotides on the DNA strands.
2. DNA replication could be achieved if the strands were unwound, with each single strand used as the template for a new strand.

Both of these possibilities turned out to be the case.



Barbara McClintock (1902-1992)



Barbara McClintock:

• McClintock studied chromosomes and how they change during reproduction in maize.
• Using microscopic analysis, she demponstrated many fundamental genetic ideas such as:

1. Genetic recombination
2. Crossing over

• She also discovered Transposition; a theory that explains how genes are responsible for turning physical charactersitics on or off.
• McClintock won the Noble Prize for her discovery that genes are able to change position on chromosomes.



Arthur Kornberg (1928-2007)



Arthur Kornberg:

• He was an American biochemist
• Through his research on enzymes, he was the first to isolate DNA polymerase, the enzyme that assembles DNA from its components, and the first to synthesize DNA in a test tube.
• Kornberg won the Noble Prize for his work in 1959.
• He later became the first to replicate an infective virus DNA in vitro.