DNA

• The four bases found in DNA are adenine (A), thymine (T), cytosine (C), and guanine (G).
• Each nucleotide has three parts: a sugar molecule (deoxyribose), a phosphate group, and one of four nitrogenous bases (adenine, thymine, cytosine, or guanine).
• DNA is the genetic material that contains all the information needed to build an organism.
• The two strands of DNA are antiparallel, meaning they run in opposite directions.
• DNA is a double-stranded molecule that forms a helical structure.
• Each base on one strand pairs with its complementary base on the opposite strand, forming hydrogen bonds between them.
• Nucleic acids store genetic information by encoding it as sequences of nucleotides.
• Protein synthesis involves two main stages: transcription and translation.
• Ribonucleic acid (RNA) differs from deoxyribonucleic acid (DNA) by having ribose instead of deoxyribose as its sugar component and uracil instead of thymine as its base.
• There are different types of RNA based on their function, including messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA).
• The sequence of bases along a single strand determines the genetic code of an organism.
• Cytosine always pairs with guanine through three hydrogen bonds.
• The sequence of nucleotides in DNA determines the genetic information carried by an organism.
• Transcription occurs inside the nucleus where RNA polymerase reads the sequence of bases on a strand of DNA and makes a complementary copy of mRNA.
• Adenine is complementary to thymine because they have similar chemical properties.
• Thymine is found only in DNA, while uracil is found only in RNA.
• Adenine always pairs with thymine or uracil through two hydrogen bonds.
• Genetic mutations can occur due to errors during replication or exposure to environmental factors such as radiation or chemicals.
• In DNA replication, two strands are made from one original double-stranded DNA molecule.
• Each base pair in DNA consists of one purine (adenine or guanine) and one pyrimidine (thymine or cytosine).
• Mutations can be beneficial, neutral, or detrimental to an individual's survival.
• During DNA replication, the two strands separate and serve as templates for the synthesis of new strands.
• The sequence of bases on the template strand determines which bases will be added to the new strand.
• During DNA replication, the two strands separate and serve as templates for new complementary strands.
• The process of DNA replication involves unwinding the helix, separating the strands, synthesizing new nucleotides, and joining them together.
• Point mutation: A change in a single nucleotide base pair within a gene.
• Errors in DNA replication can lead to genetic mutations that may have consequences on gene expression and protein function.
• The process of DNA replication is semiconservative because each daughter strand receives one old and one newly synthesized strand.
• centromere is the part of the chromosome that connects the sister chromatids
• Helicase unwinds a DNA strand
• DNA polymerase adds complementary bases to the growing chain
• The bond between a sugar and a phosphate molecule is called a phosphodiester bond and is a strong covelent bond
• A nucleotide consists of three components: a pentose (5-carbon) sugar, a nitrogenous base, and a phosphate group
• chromatin is DNA strands wrapped around histones to form chromosomes (decondensed chromatid)
• A chromatid is condensed chromatin that is coiled into a chromosome. Sister chromatids when joined create a chromosome
• Histone protiens are what DNA strands wrap arround to from chromatin
• A Karyotype is a set of chromosomes from an organism
• each chromosome holds different genes and is made up of DNA molecules
• Plasmids are small amounts of DNA in prokaryotic cells that float freely in the cytoplasm
• telomere is a short piece of DNA at the end of a chromosome that protects the chromosome from damage