Genetics (PPT from Mrs. Brenda Lee)Presentation Transcript
Genetics 101• (1)Your body is made up of ______ trillion cells• (2)Nucleus has ________ % of your genes.• (3)Mitochondria has ________ % of your genes.• (4)You have nearly ______ thousand genes• (5)Genes are small parts _______________________________________• (6)Deoxyribonucleic acid measures ________ feet long• (7)DNA is a ________ stranded molecule composed of (a) _____ (b) _______(c) ________
Genetics 101• (8)Four bases (a) ________ (b) ________ (c) ________ (d) ________• (9)These bases spell out the language known as the ________ ________• (10)Genes are ________ for making specific proteins, passed on from one ________ to another.• (11)Genes ________ a cell how to function and what traits to ________.• (12)Gene ________ turn different genes on and off in different cells to ________ cell function.
Genetics 101• (13)The long molecules of ________ containing your genes are organized into pieces called ________.• (14)Humans have ________ pairs chromosomes.• (15)Chimpanzees have ________ pairs chromosomes.• (16)Rhesus monkeys ________ pairs chromosomes.• (17)Cows________ pairs chromosomes.
Genetics 101• (18)Chickens________ pairs chromosomes.• (19)Fruit flies________ pairs chromosomes.• (20)Bananas________ pairs chromosomes.• (21)What percentage of the DNA in your chromosome do you share with other species?• (22)You share ________% of your DNA with rhesus monkey• (23)You share ________% of your DNA with chimpanzee
Genetics 101• (24)You share ________% of your DNA with other humans• (25) With the above information describe why the nucleus is the control center of the cell.
What is Genetics?• the study of inheritance. (heritable characteristics)• It can predict how genes may be passed on to future generations.
GENES• units of genetic material that CODES for a SPECIFIC TRAIT
DNA NucleotidePhosphate Group O 5 O=P-O CH2 O O N Nitrogenous base C4 C1 (A, G, C, or T) Sugar (deoxyribose) C3 C2
Nitrogenous Bases• PURINES 1. Adenine (A) 2. Guanine (G) A or G• PYRIMIDINES 3. Thymine (T) 4. Cytosine (C) T or C
DNA vs RNA
DNA vs RNA
DNA vs RNA
WATSON & CRICK• 1953; described the DNA molecule
Watson & Crick proposed…•DNA had specific pairing between the nitrogen bases: ADENINE – THYMINE CYTOSINE – GUANINE•DNA was made of 2 stands of nucleotidesarranged in pairs “Complementary Rule”
Central Dogma of Molecular Biology (1970)• Flow of genetic information from DNA to RNA to protein and is descriptive of all organisms.• Translation of a protein follows a chain of molecular command, where DNA acts as a template for both its replication and for transcription to RNA (mRNA) , which then serve as a template for translation into protein.
Central Dogma of Molecular Biology (1970)• The flow of genetic information via the three fundamental processes of replication, transcription, and translation• States that DNA makes RNA, which makes protein.• DNA – RNA - Protein
Central Dogma of Molecular Biology
REPLICATION (nucleus)The process of copying a DNA molecule STEPS 1. Unwinding of parental DNA molecule 2. Complementary base pairing Adenine = Thymine Guanine = Cytosine
REPLICATION (nucleus)3. Joining - The complementary nucleotides join to form new strands. “Semiconservative” – each daughter DNA molecule contains an old strand and a new strand; one of the old strands is conserved.
Semiconservative Model DNA TemplateParental DNA New DNA
REPLICATION (nucleus) The DNA molecule produces 2 IDENTICAL complementary strands following the rule of base.
Replication Recitation1. Why is replication necessary? A---? G---?2. When & where does replication occur? C---?3. Describe how replication works. T---?4. Use the complementary rule to A---? create the complementary strand: G---? A---? G---? C---? A---? G---? T---?
Replication Recitation 1. Why is replication necessary? A---TFor both new cells to have the correct G---Ccopy of the same DNA C---G 2. When & where does replication occur? T---A During interphase (S phase); nucleus A---T G---C 3. Describe how replication works. A---T Enzymes unzip DNA and complementary G---C nucleotides join each original strand. C---G 4. Use the complementary rule to A---T create the complementary strand: G---C T---A
TRANSCRIPTION (nucleus)STEPS 1. DNA will “unzip” itself and RNA nucleotides match up to the DNA strand. 2. After an RNA polymerase has passed by, the DNA strands rejoin and the mRNA is released.
TRANSCRIPTION (nucleus)Transcription makes messenger RNA (mRNA) to carry the code for proteins out of the nucleus (via the nuclear pore) to the ribosomes in the cytoplasm.
Central Dogma of Molecular Biology
TRANSLATION (CYTOPLASM)• The cell uses information from “messenger” RNA to produce proteins
TRANSLATION (CYTOPLASM) (1961) Watson & Crick proposed…• …DNA controlled cell function by serving as a template for PROTEIN structure.• 3 Nucleotides = a triplet or CODON (which code for a specific AMINO ACID)• AMINO ACIDS are the building blocks of proteins.
Central Dogma of Molecular Biology (1970)
The Genetic Codeconsists of 64 triplets of nucleotides. These triplets are called codons. With three exceptions (UAA, UAG, UGA), each codon encodes for one of the 20 amino acids used in the synthesis of proteins.One codon, AUG (start) serves two related functions:it signals the start of translationit codes for the incorporation of the amino acid methionine (Met) into the growing polypeptide chain
Amino Acid Translation Table
Recitation1. Why is transcription necessary?2. Describe transcription.3. Why is translation necessary?4. Describe translation.5. What are the main differences between DNA and RNA.6. Using the chart p.241, identify the amino acids coded for by these codons: UGGCAGUGC
1. Why is transcription necessary? Transcription makes messenger RNA (mRNA) to carry the code for proteins out of the nucleus to the ribosomes in the cytoplasm.
2.Describe transcription.RNA polymerase binds toDNA, separates the strands, thenuses one strand as a template toassemble mRNA.
3. Why is translation necessary? Translation assures that the right amino acids are joined together by peptides to form the correct protein.
4. Describe translation. The cell uses information from mRNA to produce proteins.
6. Using the translation table, identify the amino acids coded for by these codons: UGGCAGUGC tryptophan-glutamine- cysteine