Nucleic Acids Flashcards
Learn all about DNA and RNA (25 cards)
What does DNA stand for?
Deoxryibonucleic acid
What does RNA stand for?
Ribonucleic acid
What does DNA stand for?l
Nucleotides
A nucleotide consists of:
P- Phosphate group
S- Deoxyribose or ribs sugar
N- Nitrogenous base (adenine, cytosine or uracil)
What are the four different Nitrogenous bases of DNA
Adenine
> these two are always paird together
Thymine
Guanine
>these two are always paird together
Cytosine
What are the four different Nitrogenous bases of RNA
Adenine
>these two are always paird together
Uracil
Guanine
>these two are always paird together
Cytosine
What are the similarities of DNA and RNA
Nitrogenous bases present : Adenine, Cytosine, Guanine
What are the differences between DNA and RNA
DNA RNA
Nitrogenous
bases present :Thymine Uracil
Contains sugar :Deoxyribose Ribose
Double-stranded molecule Single-stranded
molecules
DNA replication
DNA replication takes place at interphase before mitosis or meiosis begins. It is the process during which a DNA molecule makes an exact copy (replica) of itself.
Step 1 of DNA replication
The double helix unwinds
Step 2 of DNA replication
Weak hydrogen bonds between nitrogenous bases break and two DNA strands unzip (separate).
Step 3 of DNA replication
Each original DNA strand serves as a template on which it’s complement is built
Step 4 of DNA replication
Free nucleotides build a DNA strand onto each of the original two DNA strands by attaching to their complementary nitrogenous bases (A to T and C to G).
Step 5 of DNA replication
This results in two identical DNA molecules. Each molecule consists of one original strand and one new strand.
DNA replication is important because it :
> Doubles the genetic material so it can be shared between the resulting daughter cells during cell division
> Results in the formation of identical daughter cells during mitosis.
DNA profiling
Every person except for identical twins has his/her own unique DNA profile. It can be described as an arrangement of black bars representing DNA fragments of the person.
DNA profiling is used to :
- identify criminals
- identify dead bodies
- identify relatives
- identify paternity
Protein synthesis
Is the process by which proteins are made in each cell of an organism to form enzymes, hormones and new structures for cells.
What are the 2 main processes involved in protein synthesis
> Transcription (takes place in the nucleus)
>Translation ( takes place in the cytoplasm on the
ribosome)
What happens during Transcription
- DNA unwinds and splits.
- One DNA strand acts as a template for forming mRNA.
- Free nucleotides arrange to form mRNA according to the DNA template. This process is called TRANSCRIPTION.
- The mRNA leaves the nucleus through the nuclear pores. Stage B now takes place when mRNA in the cytoplasm attaches to the ribosome.
What happens during Translation
- Each tRNA brings a specific amino acid to the mRNA. This is called TRANSLATION.
- The amino acids are linked together to form a particular protein.
How to identify DNA on a diagram
⚡double stranded
⚡look for for presence of Thymine
⚡found in nucleus only
How to identify Nuclear membrane
Has nuclear pores through which mRNA moves.
How to identify mRNA
⚡Single-stranded
⚡look for presence of Uracil
⚡ contains a a triplet of bases (codon)
found in nucleus and cytoplasm.
How to identify Ribosome
Usually mRNA attached to it.
