B2 Topic 1 - Inside Living Cells


?
  • Created by: Tulsi
  • Created on: 16-05-12 16:31

DNA

  • Every living organism has it's own unique set of genes
  • DNA is found in every cell in our body and is the same in each cell
  • DNA is like a 'blue print' for organisms
  • The correct order when zooming into a cell is:
    Cells --> Nucleus --> Chromosomes--> Gene --> DNA
    (http://education.technyou.edu.au/sites/default/files/images/bio/cell.jpg)
1 of 7

DNA Cont..

  • DNA stands for deoxyribonucleic acid
  • the bases in DNA always pair up as A-T and C-G
    (adenine - thymine  and cytosine - guanine)
  • Base pairs in a DNA molecule are held together in a double heilex by sugars and phosphates
    (http://www.mhhe.com/biosci/esp/2001_gbio/folder_structure/ge/m4/s1/assets/images/gem4s1_1.jpg)
2 of 7

DNA in depth

A molecule of DNA is shaped like a twisted ladder.
The sides of the ladder are made of a sugar called deoxyribose and phosphate groups.

They are linked together alternately: 

---sugar---phosphate---sugar---phosphate---sugar---phosphate---

(http://t2.gstatic.com/images?q=tbn:ANd9GcSCniac06yb5qn22fbWSoRt9sJZo7paRyub5BWJDyviq__SH0rbM5rJFqGY)

3 of 7

Uses Of Proteins

  • Cell Growth
  • Cell Repair

Proteins --enzymes-->amino acids
when you eat proteins amino acids go into your body

Hormones and Enzymes are Proteins 
Hormones - eg- insulin, adrenaline, testestorone
Enzymes -eg- amylase, lipase
(Enzymes end in 'ase') 

4 of 7

Protiens

Proteins are made up of long chains of tens to hundreds if amino acids joined up in a particular order.

There are about 20 different amino acids.

The order of amino acids is different for each protein, and it is this that controls the structure and function of the protein.

The DNA gives the order of the amino acids.(http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/P/Peptide.gif)

5 of 7

DNA coding strands

(http://ibmmyositis.com/transcriptionnolabel.gif) 

DNA coding strand ^^^
blue --complimentary strand (bottom)
blue -- DNA coding strand (top)
orange -- mRNA (protein synthesis)

6 of 7

Triplet Code/Coden

(http://www.brooklyn.cuny.edu/bc/ahp/BioInfo/graphics/GP.GeneticCode.GIF)

7 of 7

Comments

No comments have yet been made

Similar Biology resources:

See all Biology resources »See all Cells, tissues and organs resources »