5. DNA, RNA, Central Dogma, Protein Synthesis

DNA, RNA, Proteins

DNA, RNA, Proteins

The molecules of life

Deoxyribonucleic Acid (DNA)

The blueprint for life. It is a polymer of nucleotides. Discovered by Watson and Crick

Nitrogenous Base, Phosphate, 5-carbon sugar

Nucleotides is composed of ____________________, ________________, __________________

Purines

DNA BASES
Bases with a double-ring structure.
Adenine and Guanine

Pyrimidines

DNA BASES
Cytosine and Thymine

Thymine

Adenine always pairs with ________________

Guanine

Cytosine pairs with __________________

DNA Replication

Occurs before a cell divides. The biological process of producing two identical replicas of DNA. The resulting double-stranded DNA molecules are identical; proofreading and error-checking mechanisms exist.

DNA topoisomerase

DNA REPLICATION
First: an enzyme __________________________ untangles the coils.

Helicase

DNA REPLICATION
Next: Enzymes called _______________ "unzip" the DNA molecule exposing both strands nitrogenous bases. The DNA is separated into two strands.

DNA polymerase

DNA REPLICATION
Then: (enzyme) ________________ pairs the bases A-T and G-C. It checks work and corrects mistakes. Nucleotides are paired.

DNA ligase

DNA REPLICATION
Last: __________________ (enzyme) follows behind and bonds the nucleotides together. Two strands of DNA are created.

Ribonucleic Acid (RNA)

Very similar to DNA (repeating subunits, nucleotides). Each nucleotide contains a different sugar: Ribose. Bases are A, G, C, and U (Uracil). It is single stranded and shorter

Central Dogma

Theory that states that, in cells, information only flows from DNA to RNA to proteins.

DNA (Transcription) RNA (Translation) Protein

mRNA, rRNA, tRNA

3 different RNA molecules involved in protein synthesis

Transcription

PROTEIN SYNTHESIS
Occurs in the nucleus. Copying of genetic information from DNA to RNA.

Translation

PROTEIN SYNTHESIS
Occurs in the cytoplasm. Decoding of mRNA into a protein

Transfer RNA (tRNA)

Carries amino acids from the cytoplasm to the ribosome. Each codes for a different amino acid.

The Genetic Code

Consists of 64 codons. But only 61 code amino acids.

Codon

Each 3 consecutive bases on the mRNA is a code word, ____________, that specifies an amino acid.

Stop

Three codons act as signal to ____________ the process

AUG

One codon, ______, codes for methionine, and is also the Start signal for translation.