dna

NOTES

  • DNA(Deoxyribonucleic acid) is the basis of your inherited traits

    • Deoxy: taking off an oxygen (more stable + less likely to mutate)

    • Nucleic acids: any acids found in the nucleus

  • DNA is a polymer (made up of multiple units)

  • DNA makes up your genes and chromosomes found in the cell nucleus

    • DNA is mainly found in the nucleus, but can also be found in organelles like the mitochondria

Structure of DNA

  • Made up of Base pairs and a sugar-phosphate backbone (additional protection to reduce mutation rate)

  • The DNA molecule is made up of two strands twisted together in a double helix (double coil)

  • Is like a LEGO building: made up of 4 kinds of blocks called nucleotides

    • Each nucleotide has a sugar, phosphate, and a base (ATCG)


  • The phosphate and sugar build the backbone of the DNA

  • The bases form the rungs

  • The four bases are A, T, C, and G

    • A bonds with T (adenine + thymine)

    • C bonds with G (cytosine + guanine)

  • These bonds are hydrogen bonds: the weakest possible chemical bond


  • A segment of DNA is called a gene

  • The genetic code comes from the order of blocks (nucleotides) in

  • Each gene has the code (instructions) for putting together one protein

    • Proteins make up most of your structure (control enzymes, hormones, and muscles)

  • Chromosomes are like books (humans have 46 chromosomes)

  • Genes are like the chapters of the book (humans have about 20,000 genes)

  • The words and letters in the book are like letters (nucleotides) in the DNA (code or language of genes)

  • DNA is code to make lots of different proteins

  • Why do genes contain the code for making proteins?

  • Because you are made of proteins    

    • Your hormones / enzymes / muscles / bones / skin / hair, etc. are proteins

    • You find your chromosomes (which are made of DNA and proteins [histones]) in the nucleus of the cell

  • A chromosome is made up of DNA coiled around proteins (histones): this reduces tangling

  • Humans have 46 chromosomes in our body cells

  • Each parent contributes 23 chromosomes to offspring

  • Genes are short segments of DNA that contain the instructions for a trait in an organism

  • Each chromosome has, on average, 1000 genes, for a total of 20000 in the body


Vocab

ATCG:

  • Adenine, thymine, cytosine, guanine

  • All nucleotide bases


Base Pairs:

  • Adenine + thymine (both have 2 bonding spots)

  • Cytosine + guanine (both have 3 bonding spots)


Chromosomes:

  • Always in pairs

  • made up of coiled DNA

  • 46 chromosomes (23 mom, 23 dad)


DNA:

deoxyribonucleic acid

  • instructions on how to make proteins

  • genetic material

  • ribose sugar missing its oxygen

  • makes up gnes /chromosomes

  • found mainly in the nucleus and some in mitochondria


Double helix:

  • shape of DNA

  • twisted ladder


Exons:

  • Coding regions of genes

  • specify your characteristics (kept)


Gene:

  • Found on chromatin

  • codes for protein


Genetics:

  • Passed on from parents

  • gene instructions


Histone protein:

  • Gives chromosomes their shape

  • DNA is wrapped around


Introns:

  • everything that is NOT a gene, regulation things, evolution leftovers, protein things (thrown out)


Nucleosome:

  • DNA + proetin

  • DNA is wrapped around protein


Nucleotide:

  • ATCG

  • sugar + base + phospate


Nucleus:

  • contains DNA + genetic material of the cell

  • makes RNA and instructions of the cell


Phosphate:

  • Sides of DNA

  • together with ribose sugar


Sugar (ribose)

  • Sides of DNA

  • In both DNA and RNA