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BIOLOGY PRESENTATIONS FOR A-LEVEL, IN MULTIMEDIA JAMES BOWLES, 2001. LEFT CLICK OR PRESS SPACE BAR TO ADVANCE, PRESS P BUTTON TO GO BACK, PRESS ESC BUTTON TO END. ‘A’ Level Biology. Nucleic Acids. O. Nucleotides. A nucleotide contains:. Phosphate Group. Pentose Sugar. Base. O. O. P.
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BIOLOGY PRESENTATIONS FOR A-LEVEL, IN MULTIMEDIA JAMES BOWLES, 2001 LEFT CLICK OR PRESS SPACE BAR TO ADVANCE, PRESS P BUTTON TO GO BACK, PRESS ESC BUTTON TO END
‘A’ Level Biology Nucleic Acids
O Nucleotides A nucleotide contains: Phosphate Group Pentose Sugar Base
O O P O- O- Nucleotides The phosphate group gives the nucleotide an acidic nature
O O H H OH H Nucleotides The pentose sugar may be either Ribose (RNA) or Deoxyribose (DNA) Ribose Deoxyribose
Nucleotides There are five bases Adenine Guanine Purines Cytosine Thymine Uracil Pyramidines
O O Polynucleotides Bonds can form between carbon 3 of the pentose sugar and the phosphate group on carbon 5 of an adjacent nucleotide
O O O O O O O Polynucleotides Long chains can be built up in this way - Polynucleotides
O O O O O O O 5’ Polynucleotides The ends of these chains are named on the basis of which carbon is not involved in bonding 3’
O H H DNA Deoxyribonucleic Acid Sugar is Deoxyribose Bases are: Cytosine Thymine Adenine Guanine
O O O O O O O O O O O O O O DNA Two chains of polynucleotide run anti-parallel to one another
DNA The chains are arranged as a DOUBLE HELIX with 10 bases to each complete turn
DNA Base pairing is complimentary Adenine Thymine Guanine Cytosine The bonds are hydrogen bonds
O H OH RNA Ribonucleic Acid Sugar is Ribose Bases are: Cytosine Uracil Adenine Guanine
Messenger RNA mRNA UA A GCGUAU UG GCAUG Single-stranded, uncoiled polynucleotide
Messenger RNA mRNA UA A GCGUAU UG GCAUG mRNA is a copy of the DNA code which is exported from the nucleus
Transfer RNA tRNA Single-stranded RNA arranged in a ‘clover leaf’ shape
Transfer RNA tRNA Amino Acid binding site tRNA attaches to amino acids in the cytoplasm
Transfer RNA tRNA Anticodon The anticodon lines up alongside the appropriate codon on mRNA during protein synthesis
Ribosomal RNA rRNA This is a long length of RNA produced in the nucleolus
Ribosomal RNA rRNA It has areas of single and double helices
Ribosomal RNA rRNA In the cytoplasm it combines with proteins to form ribosomes
DNA vs. RNA DNA RNA
DNA vs. RNA DNA RNA May have single or double helix Always a double helix
DNA RNA May have single or double helix Always a double helix DNA vs. RNA Sugar is ribose Sugar is deoxyribose
DNA RNA May have single or double helix Always a double helix Sugar is ribose Sugar is deoxyribose DNA vs. RNA Bases are A, T, G & C Bases are A, U, G & C
DNA RNA May have single or double helix Always a double helix Sugar is ribose Sugar is deoxyribose Bases are A, T, G & C Bases are A, U, G & C DNA vs. RNA May be temporary Permanent
DNA RNA May have single or double helix Always a double helix Sugar is ribose Sugar is deoxyribose Bases are A, T, G & C Bases are A, U, G & C May be temporary Permanent DNA vs. RNA Chemically very stable Chemically less stable