Biology DNA structure and replication

Genetics

the study of genes and heredity (how genes are passed down from one generation to the next)

Trait

an inherited characteristic determined by the presence and expression of dominant and/or recessive alleles

Gene

a segment of DNA that codes for a protein, which in turn codes for a trait (skin tone, eye color, etc.)

Molecule

there are numerous genes in a DNA ___

Nucleus

DNA is present in the _ of all cells of living organisms

blueprint of life

DNA is often called the __

Chemical

DNA controls _ changes in cells, controls the type of cell that is formed, and contains instructions for making proteins

Proteins

responsible for all cell structures and functions; responsible for hair, skin, hormones, muscle movement, antibodies, chemical reactions, and oxygenation of cells

amino acids

proteins are made up of long chains called _

20

how many amino acids are there in the body

essential to all life on earth, medicinal benefits, development of crops for food, forensics

why do we study DNA?

deoxyribonucleic acid

what does DNA stand for

Nucleotides

DNA is made up of two long chains of millions of ___ (sub-units)

2

how many long strands of nucleotides are there in DNA

Hydrogen

DNA is made up of Sugar (deoxyribose) and phosphate chains on the outside, held together by _ bonds between nitrogenous bases on the inside

phosphate group, deoxyribose, nitrogen base

parts of a nucleotide

Purines

bases that contain two rings of carbon and nitrogen atoms

adenine and guanine

which bases are purines

Pyridamines

bases that contain one ring of carbon and nitrogen atoms

thymine and cytosine

which bases are pyridamines

A=T (2), C=G (3)

base pair rules

double helix

the two strands of DNA twist around a central axis to form a _

Rungs

the nitrogen bases; the steps or the ladder in the middle of DNA

CTTATG

the complementary strand to GAATAC

ribonucleic acid

RNA stands for ___

rna consists of only one strand of nucleotides, rna has ribose instead of deoxyribose, rna has uracil instead of thymine

differences between RNA and DNA

A=U, C=G

base pairing rules for RNA

3 meters

each cell has about of DNA

300 trillon

the average human has _ cells

400

The average human as enough DNA to go from the earth to the sun more than ___ times

150 billion meters or 93 million miles

the earth is ___ from the sun

0.000000002

DNA has a diameter of only ____________________ m.

so that each daughter cell in cell division can have a complete set of DNA

why does DNA replicate?

hydrogen bonds

when DNA replicates, it needs to break the _ between the bases

unwind, unzip, hold open, base pairing, proofread, joining nucleotides

DNA replication process

Topoisomerase

the enzyme that unwinds DNA, uncoiling the coiled strands

Helicase

the enzyme that unzips DNA by breaking the hydrogen bonds between its nitrogenous bases; it also creates the template/parent strand for replication

single strand binding proteins

hold open the DNA strands during replication

DNA polymerase 3

"the builder" which bonds free nucleotides on each template/parent strand using base pairing rules

5 --> 3

DNA polymerase 3 builds from the _________ carbon end in parent strands

primer, primase

the ___, made of ____ shows DNA polymerase 3 where to build

DNA polymerase 1

_ proofreads new strands of DNA during replication and backtracks to correct errors

Okazaki

small segments/ spaces in DNA on the lagging strand

DNA ligase

_ bonds that backbone together at the end of DNA replication

2 identical semiconservative DNA molecules

results of DNA replication

Mutations

if there is a mistake in replication, can occur

Semiconservative

you have an old strand and a new strand

Complementary

__ base pairing results in double stranded DNA

Anti-parallel

both DNA strands run to each other; means oriented in opposite directions

5 --> 3, 3 --> 5

one strand runs _____, while the other runs ____

replication fork

directional movement of replication

leading strand

Nucleotides are added in the same direction as the replication fork, creating a continuous _

lagging strand

Nucleotides added in the opposite direction as the replication fork create spaces and are called the __

Monomer

building blocks of macromolecules

amino acid

the monomer of protein

Nucleotide

the monomer of nucleic acids

Enzyme

a type of protein / catalyst that speeds up a chemical reaction