Translation

Act 1 :Initiation

- mRNA is moved out of the nucleus into the ribosome on the endoplasmic reticulum
- the ribosomes are made up of 2 subunits large and small.
- in eukaryote cells the they are the 40s and 60s subunits
- in prokaryote cells they are the 30s and 50s subunits
- The larger subunit contains 3 sites, A, P, and E
- The tRNA moves into the first site and reads the mRNA starting with AUG(codon)

Act 2 :Elongation

- tRNA contains anti codons that bind with the codons
- each tRNA contains a peptide that binds with the codon
- once the peptide binds with the codon it moves to the P site and picks up al the peptides that were previousely in the P site.
- the previouse tRNA moves to the E site and exits the ribosome
- this creates a chain of petides called polypeptides
- there are 64 different codons but only 20 amino acids. Every amino acid is responsible for 2-3 codons. This effect is called the wobble effect

Act 3 :Termination

- 3 base sequences can signal the stop of the translation
- the last tRNA moves to the P site and binds its peptide with the polypeptide chain
- once the translations stops, the ribosome breaks up again leaving behind the polypeptide chain that will later become protien

Transcription

Act 1 :Initiation

- The transcription factors locate the promoter (TATA) and the terminator (AAAUAAA) and begin the process of transcribing pre-mRNA.
- The strand being used to make the pre-MRNA is called the template or antisense, the other strand s called the coding or sense strand
- the initiation complex is made by RNA polymerase II

Act 2 :Elongation

- When being copied, th pre-mRNA is the same as the coding strand except that the T's are replaced with U's
- The pre-mRNA strand starts from the (TATA) sequence and stops at the termination sequence (AAAUAAA) in a 5' to 3' direction

Act 3 :Termination

- Once the Polymerase II reaches the terminator sequence the pre-mRNA cuts off and the DNA twists back together
- The pre-mRNA is guarded by a G-cap at the 5' end and a poly-A tail on the 3' end
- the useless introns are taken out of the pre-mRNA by splicosomes made up of proteins and SnRNP's.

DNA Replication

The process of replicating DNA requires several enzymes and proteins. By separating the process into parts such as Initiation, Elongation and Termination we make it easier to understand.

Initiation
As we all know DNA is in a form of a double helix, so before replication begins we have to first unwind that double helix. To unwind the DNA we use the enzyme Helikase. As soon as the DNA become unwound they also become single-stranded. When DNA is single stranded they become weak and can break easily. This is when singe stranded binding protiens come in to stabilize the DNA. Lastly we have the enzyme Gyrase that releases the tension from the DNA.

Elongation
Elongation starts when primase puts down a primer on the DNA. This primer acts as a signal that DNA polymerase can latch onto. In the leading end DNA polymerase III moves across the DNA from 5' to 3' and copies the genetic code from the parent strand. Polymerase I also helps by proofreading the daughter strands code and making sure it matches with the parent strand. However int he lagging end, DNA has to be copied discontinuously. Primase has to put down primers multiple times and Polymerase III has to latch onto those primers and copy genetic code only in small segments.

Termination
During the last step, Termination DNA ligase joins the okasaki fragments and completes the lagging end of the daughter DNA strand.

Anabolism - Metabolism - Catabolism

Anabolism - is the set of metabolic pathways that construct molecules from smaller units. These reactions require energy. Usually require energy from ATP.

examples :

Cyclic Cycle

Calvin Cycle

Non Cyclic Cycle

Metabolism: is the set of life-sustaining chemical transformations within the cells of living organisms. These enzyme-catalyzed reactions allow organisms to grow and reproduce, maintain their structures, and respond to their environments.


Catabolism: is the set of metabolic pathways that breaks down molecules into smaller units to release energy.

Examples:

Glycolisis

Kreb Cycle

Rafflesia

The ROM is one of the best museums in Canada and on Oct 31st my biology class and I were given the privilege to attend a tour. During the tour what amazed me the most was a flower called the Rafflesia.

The Rafflesia is the worlds heaviest flower and surprisingly this flower has no stems leaves or true roots. The Rafflesia is also sometimes known as the corpse flower because it gives off the smell of rotting flesh. Other flowers release a descent scent in order to attract insects for pollination. The fact that the Rafflesia has a rotting scent indicates that the insects it targets are flies and other organisms attracted to the smell of rotting.

The rafflesia that was on display at the ROM was unfortunately a life sized replica. Having a real flower in a museum would be unrealistic as it would probably wilt and die.Other than smelling like a corpse the Rafflesia is also known for having no leaves and stems. The red petals on the flower show that it cant photosynthesis. How can a plant survive without phphotosynthesis. The Rafflesia is actually a parasite. It has roots however these roots dont get minerals from the soil, the Rafflesia's roots suck nutrients from other plants. It is with this method that the Rafflesia has no need to photosynthesis. The Rafflesia also has very strict blooming seasons, it will only bloom once a year and wilt in around 3 days. The Rafflesia blooms have to be synchronized or else pollination bettween males and females wont occur.

ETC - 10 facts

• PS II & PS I need sunlight to get excited

• Breaking apart of water molecules is called photalysis

• PS II passes the electrons to plastoquinone (PQ) to transport the electrons to the cytochrome

• B6F passes the electrons from the PQ and send it off to Plastocyanin to distribute it to PS I

• PS II and PS I are photo systems which means they need sun to activate

• PS I was discovered before PS II 

• PS I passes its electron to ferredoxin and ferredoxin become reduced

• NADP becomes negative after an electron passes through it, the positiv Hydrogen molecules bond with it making NADPH

• ADP synthase bonds with Adenine and two phosphate molecules to form the adenine diphosphate (ADP); these begin spinning quickly allowing the excess hydrogen to exit the leaf. This movement of the hydrogen atoms causes the spinning to slow down.
• The third phosphate bonds with the ADP to form ATP 

Pig Dissection Review

This week my bio class was given the opportunity to dissect a fetile pig. This dissection was supposed to further our understanding of multiple body systems by giving us a more real view of what each body system actually looks like and where they are positioned throughout the body.

This is a picture of what the fetile pig looked like before the dissection begun. We were asked to determine the sex of the pig and came to understand that ours was female which gave us the thought of trying to find the ovaries.

We started by making an incision right under the rib cage to try and isolate liver, pancreas, kidneys, heart, lungs and ovaries

After opening up the pig's belly we began to isolate individual body parts

The Kidney

The Heart

cross section of the heart

An ovaries

The liver

After isolating all the parts in the belly of the pig Day 2 of the dissection began. This time our goal was to get the brain, lens and thyroid. Our group failed to locate the thyroid because everything looked the same, same color same texture we couldn't differentiate whether it was thyroid or fat or tissue.


Everything around the thyroid was the same color and texture so identifying the thyroid was too difficult a task for us


We began on the brain by cutting off the skin and splitting the skull




Our isolated brain was actually in excellent condition, our group took extra care not to damage it during the extraction process

Next, we began the extraction of the eyes and lens





After taking out the eye we had to cut it in half to get to the lens


Our final isolated lens