Helpful Video on Digestive System

http://www.youtube.com/watch?v=Z7xKYNz9AS0

CELL PROCESSES

Unit 2- Cell Processes                                                                                                      Kriti Chopra

Protein Synthesis

TRANSCRIPTION

1. The cell gets a message to make a certain quantity of specific protein. 

2. A portion of the DNA molecule unwinds, exposing the gene responsible for the protein.

3. Nucleotides, with the help of enzymes , move along one strand of the exposed gene and form a molecule of m-RNA. U pairs with A in the RNA.

4. Multiple copies of m-RNA are made according to the quantity of the order.  They leave the nucleus and enter the cytoplasm through nuclear pores.

5. An m-RNA binds with a ribosome so that the m-RNA can be read by the ribosome.

6. The message is read three nucleotide bases at a time. Each codon or triplet code stands for a specific amino acid activated by an enzyme.

TRANSLATION

7. The transfer RNA molecule has TWO ends.  One end has specific binding site for particular amino acid. The other end has a sequence of three nucleotides, the anticodon that can base pair with a codon.

8. The appropriate molecule of t-RNA attaches to and carries activated amino acid to the ribosome. And anticodon base pair with codon in order to bring the specific amino acid to the correct place.

9. A second transfer RNA picks up another activated amino acid and brings it to the ribosome, matching the anticodon to codon.

TERMINATION

10. First t-RNA releases its amino acid to the second transfer RNA and leaves the site. ( They form peptide bonds using ATP.

11. The second t-RNA releases its “load” of amino acids to the third t-RNA and leaves sight,

12. This process repeats itself until the entire message is read through

Helpful video to understand Protein Synthesis

http://www.youtube.com/watch?v=NJxobgkPEAo

Respond to my mark

I am quiet disappointed with my mark because I am not doing as well as I expected. However I am missing a blog and a lab. I will also redo my RNA and DNA to recieve a better mark . Furthermore I need to study more and keep ups with my assignments to recieve a better grade in biology. Hopefully, by the end of the semester I will be able to touch the 80 percent range

Cellular Respiration

Mitochondrion is a membrane enclosed organelle found in most eukaryotic cells. It contains an outer and inner membranes composed of phospholipids bilayers and proteins. The main function of mitochondrion is the production of energy, in the form of ATP, The cell uses this to perform the specific work necessary for cell survival and function. The tissues in the body are broken down into simpler molecules such as carbohudrates, fats and protein in called metabolism. 

Some other interesting things about mitochondria are :

It is the second largest organelle with unique genetic structure
- Double-layered outer membrane with inner folds called cristae
- Energy-producing chemical reactions take place in here
- Controls level of water and other materials in cell
- Recycles and decomposes proteins, fats, and carbohydrates, and forms urea

RNA

Cell Membrane

Phospholipids are a class of lipids that are a major component of all cell membranes as they can form lipid bilayers. Phospholipids consists of a somewhat circular phosphate group head, and two long, fatty acid chain tails.

·         The head region is said to be Hydrophilic and polar because it is water soluble, while the tail portions are hydrophobic and no polar because they are not water soluble.

Another Type of lipid that is found within the lipid bilayer is the Cholesterol Molecule. Cholesterol helps to maintain in fluid condition of the bilayer by breaking up the closely associated phospholipids.

Proteins that are embedded in the cell membrane carry out various cellular functions such as nutrient and energy transport and message transmission.

·         Integral Protein has the span if the entire width of the lipid bilayer and protrudes at both sides. They are used as channels through which ions and molecules can travel into and out of the cell.

·         Alpha Helix Protein extends through the membrane, and acts as a channel for nutrients entering the cytoplasm.

Glycoproteins consist of a protein with an attached carbohydrate. The carbohydrate molecules are involved in cell recognition as receptors, and they also aid in the cell’s adhesion to other cell.

Glycolipids are lipids with a carbohydrate attached. Their role is to provide energy and also serve as markers for cellular recognition.

DNA