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Presenting: DNA and RNA. DNA stands for Deoxyribonucleic acid 1. It belongs to the class of biochemical molecules known as nucleic acids. 2. It is made up of atoms of : C arbon H ydrogen O xygen N itrogen P hosphorous. Importance of DNA
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DNA stands for Deoxyribonucleic acid 1. It belongs to the class of biochemical molecules known as nucleic acids. 2. It is made up of atoms of : Carbon Hydrogen Oxygen Nitrogen Phosphorous
Importance of DNA • It carries genetic information from one generation to the next. • DNA sequences create genes which then determine inherited traits. • DNA can be easily copied during the creation of new cells.
Where is DNA located? Chromosome DNA double helix Histones
Regents Practice Question #1 The diagram below represents levels of organization within a cell of a multi-cellular organism. The level represented by X is composed of (1) four types of base subunits (2) folded chains of glucose molecules (3) twenty different kinds of amino acids (4) complex, energy-rich inorganic molecules
Regents Practice Question #1(Answer) The diagram below represents levels of organization within a cell of a multi-cellular organism. The level represented by X is composed of (1) four types of base subunits (2) folded chains of glucose molecules (3) twenty different kinds of amino acids (4) complex, energy-rich inorganic molecules
Regents Practice Question # 2 Which model best represents the relationship between a cell, a nucleus, a gene, and a chromosome?
Regents Practice Question # 2 (Answer) Which model best represents the relationship between a cell, a nucleus, a gene, and a chromosome? Correct Answer
Regents Practice Question # 3 Which diagram represents the relative sizes of the structures listed below?
Regents Practice Question # 3 (Answer) Which diagram represents the relative sizes of the structures listed below? Correct Answer
Structure of DNA • 1. DNA is a long molecule made up of units called nucleotides. • 2. Each nucleotide is made up of three basic parts: • 5-carbon sugar (deoxyribose) • phosphate group • nitrogenous base
N U C L E O T I D E
There are 4 kinds of Nitrogenous bases Adenine phosphate Guanine Cytosine 5 carbon sugar Thymine
DNA is a double helix in which two strands are wound around each other. Nucleotide Hydrogen bonds Sugar-phosphate backbone Key Adenine (A) Thymine (T) Cytosine (C) Guanine (G)
Complimentary Base Pairing • 1. The two DNA strands are held together at the nitrogenous bases by weak hydrogen bonds. The bases will always pair up in the following way: • Adenine bonds to Thymine A-T • Cytosine bonds to Guanine C-G • 2. Francis Crick and James Watson published the structure of the DNA molecule in 1953.
Check for Understanding of DNA Structure • What is the name of the sugar? • What is the symbol used to represent the sugar? • 3. Name the 4 nitrogenous bases. • 4. Name the complimentary base pairs. • 5. What type of bonds hold the bases together?
Check for Understanding of DNA Structure (Answers) • 1.What is the name of the sugar? deoxyribose • What is the symbol used to represent the sugar? • 3. Name the 4 nitrogenous bases. • adenine, thymine cytosine, guanine • 4. Name the complimentary base pairs. • adenine – thymine • cytosine - guanine • 5. What type of bonds hold the bases together? • hydrogen bonds
When will DNA replication occur? • DNA replication is the process of copying a DNA molecule • DNA must replicate during cell division so that the genetic information can be passed to the daughter cells. • In order to direct cell functions DNA must replicate itself and send the information out of the nucleus because the DNA is not permitted to leave the nucleus.
The DNA separates into 2 strands. It unzips itself with the help of an enzyme called DNA polymerase. • Each parent (old) strand serves as a template (model) for making a new DNA strand complimentary to itself. • Replication results in 2 daughter strands each consisting of an old DNA strand and a new DNA strand. DNA Replication Process
Your Turn! DNA Replication Following base pairing rules, create a new DNA molecule A T C G T A G C A T T A C G G C A T C G T A G C + Parent New New Parent DNA Polymerase Unzips the DNA
Regents Practice Question # 4 Several structures are labeled in the diagram of a puppy shown below. Every cell in each of these structures contains (1) equal amounts of ATP (2) identical genetic information (3) proteins that are all identical (4) organelles for the synthesis of glucose
Regents Practice Question # 4 (Answer) Several structures are labeled in the diagram of a puppy shown below. Every cell in each of these structures contains (1) equal amounts of ATP (2) identical genetic information (3) proteins that are all identical (4) organelles for the synthesis of glucose
Regents Review Question # 5 Mustard gas removes guanine (G) from DNA. For developing embryos, exposure to mustard gas can cause serious deformities because guanine (1) stores the building blocks of proteins (2) supports the structure of ribosomes (3) produces energy for genetic transfer (4) is part of the genetic code
Regents Review Question # 5 (Answer) Mustard gas removes guanine (G) from DNA. For developing embryos, exposure to mustard gas can cause serious deformities because guanine (1) stores the building blocks of proteins (2) supports the structure of ribosomes (3) produces energy for genetic transfer (4) is part of the genetic code
Importance of Protein • Protein is found everywhere in your body. • Every single cell, tissue, muscle and bone contains protein. Protein is essential for providing bone and muscle strength, endurance and immunity. • It is estimated that the human body may contain over two million proteins. Sickle Cell Disease
Protein Synthesis 1. Genes control the production of proteins which occurs on the ribosomes. 2. Each gene directs the production of a specific protein or special proteins such as hormones and enzymes. 3. The DNA can’t leave the nucleus but it needs to send instructions to the ribosome so proteins can be made. 4. The DNA sends a messenger out to the ribosome that carries the instructions for making the proteins.
What is RNA ? • RNA is the messenger that carries the instructions to the ribosome so proteins can be made. • It is very similar to a DNA molecule but yet different enough that it can cross the nuclear membrane without being recognized as DNA.
Structure of RNA • The sugar in the nucleotide is ribose. • It is single-stranded. • It has uracil for a nitrogenous base instead of thymine. • Complimentary base pairs are: • Cytosine – Guanine C-G • Adenine – Uracil A-U
Making a Protein starts with Transcription Transcription is the name given to the process where a DNA molecule makes the messenger RNA molecule in the nucleus. Adenine (DNA and RNA) Cystosine (DNA and RNA) Guanine(DNA and RNA) Thymine (DNA only) Uracil (RNA only)
Translation happens when mRNA arrives at the ribosome • During translation, the cell uses information from mRNA to produce proteins that are built from amino acids. • 2. Two other types of RNA are involved: • Transfer RNA ( tRNA) brings amino acids to the ribosome • Ribosomal RNA (rRNA)makes up the ribosome
Translation from RNA into Protein Nucleus Transcription of Messenger RNA Lysine mRNA Phenylalanine tRNA Methionine Translation by Transfer RNA Ribosome Start codon mRNA
The Genetic Code • Codons are located on the mRNA • 2. A codon consists of three nitrogenous bases that code for a single amino acid that is to be added to the growing protein chain. • 3.There are just 22 different amino acids that exist. • . • Example of codons: • AUG is the start codon that gets the process going • UUC codes for Phenylalanine • AAA codes for Lysine
Regents Practice Question # 6 The diagram below shows some of the steps in protein synthesis. The section of DNA being used to make the strand of mRNA is known as a (1) carbohydrate (2) ribosome (3) gene (4) chromosome
Regents Practice Question # 6 (Answer) The diagram below shows some of the steps in protein synthesis. The section of DNA being used to make the strand of mRNA is known as a (1) carbohydrate (2) ribosome (3) gene (4) chromosome
What are Mutations? • 1. Mutations are changes in the genetic material of the cell. (DNA) • 2. Mutations can be good, bad or neutral. • 3. There are 3 different types of mutations: • substitutions • insertions • deletions
Substitutions Substitutions occur when one nitrogenous base is substituted in place of another one. • Result: • 1.Most likely there will be no change in the protein made. • 2.This mutation only affects one amino acid in the long sequence of a protein. • 3. It is the least harmful.
Example of a Substitution: THECATSAWTHEDOG THE CAT SAW THE DOG THE BAT SAW THE DOG THE CAT SAW THE HOG THE CAT SAT THE DOG
Insertions Insertions occur when one extra nitrogenous base is added into the DNA sequence. • Result: • BAD • All the nitrogenous bases after the insertion will be regrouped into different codons. • The protein made will be nonfunctional.
Example of an insertion: THECATSAWTHEDOG THECCATSAWTHEDOG The letter C was inserted THE CCA TSA WTH EDO G
Deletions Deletions occur when one nitrogenous base is missing from the sequence. • Result: • BAD • 2. All the nitrogenous bases after the deletion will be regrouped into different codons. • 3. The protein made will be nonfunctional.
Example of a Deletion THECATSAWTHEDOG THCATSAWTHEDOG The letter E was missing THC ATS AWT HED OG
Regents Practice Question # 7 The diagram below shows a normal gene sequence and three mutated sequences of a segment of DNA. Which row in the chart below correctly identifies the cause of each type of mutation?
Regents Practice Question # 7 The diagram below shows a normal gene sequence and three mutated sequences of a segment of DNA. Which row in the chart below correctly identifies the cause of each type of mutation? Correct