science yap

dna is the blueprint of all life and every organism has DNA its a nucleic acid— nucleic acid is when nucleotides form together they form a long polynucleotide chain called an nucleic acid, it stores the information on how a cell works the shape of DNA is a double helix, “twisted ladder” which are made of complementary nucleotide— they are subunits of DNA, made up of deoxyribose sugar, phosphate and a nitrogen base, there are 4 nitrogen bases in DNA that have a complmentary so they can only be with each other, Adenine and Thymine, Guanine and Cytosine. The nitrogen bases are hydrogen bonded which is a intermolecular bond which is weak. They are the “runs” of the DNA. The sugar phosphate backbone of the DNA are connected with a covalent bond which are a chemical bond between atoms. Gene is a specific part of DNA that codes for a particular protein. Chromosomes are long DNA molecules coiled up wrapped around histones. homologous chromosomes are a pair of chromosomes a person has, one paternal and one maternal. a human karyotype is a display showing all 46 chromosomes a person has.

DNA VS RNA

mRNA: copies sections of DNA

rRNA: forms the ribosome

tRNA: carries AA to ribosome to assemble a polypeptide (chain on AA)

DNA replication creates an exact copy before cell division. There are three enzymes that participate in DNA replication. DNA Helicase which “unzips” the parental DNA. New nucleotides get added to each strand using DNA polymerase, assembling them. Then DNA Ligase binds the sugar-phosphate.

Mutations are spontaneous, permanent changes to the structure of DNA, causing a new alleles. This happens due to mutagens which are agents that cause mutation (e.g chemical / radiation)

mitosis vs meiosis

MITOSIS: IPMAT

Interphase

Prophases

Metaphase

Anaphase

Telophase