BIOLOGY TEST (SYBAU ICL TS PMO SMH)

How does messenger RNA know what to copy?

DNA tells it what to copy

What are the three combinations of nucleic acids that go together called?

codon

What happens if a nitrogen base is missing or an extra one is inserted?

a mutation

What are three types of mutations?

Point/substitution mutations, Deletion mutations, Insertion mutations

Where does protein synthesis occur?

ribosomes

What is the first step in DNA replication?

the double helix unzips

What is another word for protein?

peptide

What are the two steps in protein synthesis?

transcription and translation

Which one comes first: transcription or translation?

transcription

How many amino acids are there?

20

What are the 3 types of RNA?

mRNA (messenger, biggie) to the ribosomes, tRNA (transfer RNA brings it back inside the ribosomes), rRNA (ribosomal RNA found in ribosomes)

What does uracil replace in RNA?

thymine

What are three characteristics of RNA?

single stranded, one more oxygen, has uracil instead of thymine

Where do mutations occur?

in the DNA sequence

What’s the difference between transcription and translation?

transcription comes first (rewrite), translation (change into protein)

Where does most of protein synthesis happen?

ribosomes

What tells mRNA what to copy?

DNA

In the ribosome, what type of RNA chooses the nitrogen bases?

rRNA

Where is rRNA found?

in ribosomes

What does tRNA do?

transfers nitrogen base information

If the DNA has CAT nitrogen bases, what is the mRNA codon?

GUA

What are the functions of mRNA?

template or to give the codon, carries genetic information

What are the three components of a DNA strand?

sugar, phosphate, nitrogen base

What holds the two nitrogen bases together?

hydrogen bonds

What kind of bond is hydrogen?

weak

What is the first thing that happens in DNA replication?

the double helix unzips

A characteristic of DNA is…?

DNA replicates, protein builds

What are the four stages of a protein molecule?

1. Primary: amino acid chain, 2. Secondary: folds into coils or sheets, 3. Tertiary: 3D folded shape, 4. Quaternary: multiple protein chains connected