DNA/RNA/Protein synthesis - notes -

What are the 4 nitrogen bases of DNA

Adenine, thymine, guanine, cytosine

What is the macromolecule of DNA

nucleotides

Each nucleotide in DNA contains…

a sugar, a phosphate group, and a nitrogen containing base (ATGC)

What holds together two complementary chains of polynucleotides  

Hydrogen bonds

Whats DNA replication

Process in which DNA is replicated

When does Dna replication occur

the eukaryotic cell cycle

1st step of DNA replication

when an enzyme (Dna helicase) breaks the bonds between bases in DNA

2nd step of DNA replication

The DNA is exposed so they can be “read” by another enzyme, (polymerase)

3rd step of DNA replication

1 strand (original) is used to build two new DNA strands with complementary 

Dna replication is a …… process

semi conservative because half of the parent DNA molecule is conserved in each of the two daughter DNA molecules.

What part of the nucleotide is this?

The sugar (deoxyribose)

What part of the nucleotide is this?

Phosphate group

What part of the nucleotide is this?

Nitrogen containing base

What type of biological molecule is DNA helicase

An enzyme

What type is DNA replication, where two different DNA strands are created each with half of the original DNA

Semi-conservative replication

4 stages of the cell cycle

G1​, S, G2​, and M

In the cell cycle what cycles are called “interspace”

The first three stages

This is the cell's main growth phase. The cell is getting bigger and doing its normal everyday work (like a skin cell protecting your body, or a liver cell filtering blood).

At the end of G1​, if you could see the DNA, you'd see the homologous chromosomes (the two versions of each chromosome, one from each parent) visible.

G1 (gap 1)

Who was the first person to actually isolate DNA from cells

Friedrich Miescher

This is the most important part of preparation: the cell copies all of its DNA (chromosomes). This is called DNA replication.

• After this stage, every chromosome is now doubled, ready to be split evenly between two new cells.

S (Synthesis)

The cell continues to grow and makes any last-minute proteins and organelles it needs to complete division. It's double-checking everything before the big event.

At the beginning of the next stage (M), the duplicated chromosomes condense (coil up tightly) and you can clearly see the "X" shape, where the two identical copies (sister chromatids) are joined at the center (centromere).

G2​ (Gap 2)

This is the stage where the cell actually divides. It first separates the duplicated DNA (mitosis) and then splits the rest of the cell contents (cytokinesis) to form two identical daughter cells.

The two new cells then go back to the beginning of the G1​ phase to start the cycle all over again!

M (Mitosis): Cell Division

1st step of protein synthesis

Transcription

3 differences between DNA and RNA

They have different sugars. They have different bases. Different structure

What sugar does DNA and RNA have

DNA- deoxyribose       RNA- ribose

What is the difference in the bases of DNA and RNA

DNA has a-t-c-g and RNA has a-U- c-g (a pairs with u)

Transcription occurs in the……. of eukaryotic cells

Nucleus - because Dna is stored in nucleus but too large to pass through the pores in the nuclear membrane

Step 1 of Transcription

Dna unwinds/unzips at a specific gene

step 2 of transcription

free floating RNA nucleotides match with COMPLEMENTARY DNA bases

step 3 of transcription

when the mRNA transcript is completed it leaves the nucelus

step 4 of transcription

DNA molecule zips back up and winds back up

DNA alone cannot ‘‘tell’’ your cells how to make proteins. It needs the help of RNA

DNA alone cannot ‘‘tell’’ your cells how to make proteins. It needs the help of RNA

what are the 3 types of RNA

Messenger RNA (mRNA)

Ribosomal RNA (rRNA)

Transfer RNA (tRNA)