CO 14

Chapter 12: Genotype Phenotype

GENES SPECIFY ENZYMES

GENES SPECIFY PROTEINS

The Central Dogma  DNA   RNA  Amino Acid (Protein)

Figure 14.3

RNA is a lot like DNA, except: 1. Ribose2. Uracil3. Single Strand *Can leave the nucleus, carries the "message" 

Figure 14.5

Every 3 bases on mRNA  (messenger RNA) is called a CODON Each CODON specifies one AMINO ACID   Chains of amino acids are proteins          (ex.  hemoglobin)

Figure 14.6

TRANSCRIPTION:  The process where mRNA is made from DNA Follows base-pair rulehas uracil instead of thymine RNA polymerase is used to build the strand of RNA

Transcription Animations

Transcription: Stolaf.eduTranscription:  University of NebraskaTranscription: Concord.org

Translation:  process by which protein is built from the mRNA tRNA is used to build an amino acid chain

Each 3 bases on mRNA codes for a single amino acid. 

3 bases on mRNA      = a codon

Matching 3 bases on tRNA    = anticodon

tRNA has a single attached amino acid

Translation occurs on the ribosome

mRNA is threaded through the small and large subunit

Figure 14.10b

Each tRNA delivers an amino acid which binds to the previous amino acid, eventually forming a long chain .....a PROTEIN

All genes start with AUG, also called the START CODON

It attaches to anticodon UAC and the amino acid methionine

Figure 14.12

Figure 14.13

The Big Picture  (aka The Central Dogma)

Figure 14.4

Animations of Translation

Translation: Stolaf.edu 

Translation: University of Nebraska

Translation: Concord.org

Figure 12Bc

Figure 12Bda

Figure 12.10a

NONDISJUNCTION CHANGES

CHROMOSOME NUMBERS

Figure 12.10b

NONDISJUNCTION CHANGES

CHROMOSOME NUMBERS

Figure 12Bdb

Figure 12.11 DOWN SYNDROME & Gart Gene

Figure 12.11b

Figure 12Ba

Figure 12Bb

Figure 12.12a

Figure 12.12b

Trisomy 18 - Edward's Syndrome• Failure to grow and gain weight at the expected rate and severe feeding difficulties,

diminished muscle tone and episodes in which there is temporary cessation of spontaneous breathing

• Developmental delays and intellectual disability• A prominent back portion of the head, low-set, malformed ears, an abnormally small

jaw, a small mouth an upturned nose, narrow eyelid folds, widely spaced eyes, and drooping of the upper eyelids

TRISOMY 13 (also known as Patau syndrome) - Of all babies born with the extra copy of chromosome 13 in all the cells of their body, around 50% die in the first month, and the rest within the first year Median survival age for children with Patau syndrome is 2.5 days

CHROMOSOME MUTATIONS

Figure 12.13

Figure 12.13a

Figure 12.13b

Figure 12.13c

Figure 12.13d

Figure 12.14

DELETION MUTATION (WILLIAMS SYNDROME)

Williams Syndrome –

Deletion of Chromosome 7

Figure 12.16

Figure 12.16b

CRI DU CHAT

Deletion of Chromosome #5

FRAGILE X - duplication mutation