ib Bio Water+Nucleic Acids

Water has important solvent properties

Explain these properties using an example to illustrate your answer

Water has important solvent properties

Explain these properties using an example to illustrate your answer

Water molecule is polar

Water forms hydrogen bonds with other polar substances

Positive pole of water is attracted to negative ions

Glucose dissolves in water because its polar

Calculate the change of temperature in each cup after 20 minutes

State the two conditions that must be the same for each cup

• Uncovered: 50 degree Celsius

• Covered with wet tissue: 55 degree Celsius

• Volume/amount of water

• Size of the container/shape of the container

• Temperature of water

• Location/enviornment of the cup

State two structural functions that differ between DNA and RNA

• RNA is single stranded while DNA is double stranded

• RNA has uracil while DNA has thymine

• RNA has ribose sugar while DNA has deoxyribose sugar

Outline the role of enzyme helicase in replication

Outline the role of enzyme DNA helicase in replication

• Unwind the double helix to break the hydrogen bond

• Uses pre-existing strands of DNA as template strand

• Links nucleotides together to form new DNA strand

• Makes covalent bonds between the nucleotides

Outline the stages in the production of mRNA by transcription

• DNA is unwinds and the strands are separated by RNA polymerase

• New nucleotides attach to template strands by RNA polymerase

• Complementary strands pair Adenine with Uracil and Guanine with Cytosine

• DNA needs to rewind

Explain the process of translation in cells

• Translation is the convergence of base sequences on mRNA into an amino acid

• mRNA attaches to ribosome

• tRNA anticodon binds to the codon in mRNA

• Each tRNA carries a specific amino acid

• Each tRNA has a specific anticodon

• tRNA anticodons binds to codon on mRNA by complementary base pairing

• Second tRNA anticodon binds to next codon

• Two amino acids bind together by peptide bond

• The first tRNA detaches

• Ribosome moves along the mRNA

• Continues until stop codon is reached

Hershey and Chase experiment

• Proved DNA was the genetic material

• DNA contained radioactive phosporus while RNA contained radioactive sulfur

• Radioactive phosporus infected the non radioactive bacteria

• Radioactive sulfur did not cause any radioactivity

Outline the structure of a DNA molecule

• DNA is a double stranded        

• Contains deoxyribose sugar

• Has 4 bases : Adenine, Thymine, Guanime and Cytosine

• DNA is a double helix

• Contains nucleoties

• Strands are antiparallel

• Base paring rules of Adenine to Thymine and Guanime to Cytosine

• Covalent bonds between phosphate group

Draw a DNA/RNA Nucleotide

Label-Phospate,Sugar and Base

Draw a water molecule

Label-Bonds