Chapter 13- DNA: the code for life Flashcards
what is DNA?
a molecule in the nucleus of a cell that determines the types of protein that a cell can make
what are histones?
a special protein around which DNA is coiled to form chromatin
what is chromatin?
a tangled network of DNA in the nucleus of a cell that is not dividing
what are chromosomes?
one of the 46 rod-like structures that appear in the nucleus of a human cell at the commencement of cell division
what are genes?
the factor that determines a hereditary characteristic; part of a chromosome
what is a double helix?
the spiral shape of a DNA molecule
what is a nucleotide?
units of sugar, phosphate and nitrogen base that make up the DNA molecule
what are the 4 base pairs?
adenine- thymine
cytosine- guanine
what is replication?
the process by which a DNA molecule forms an exact replica of itself
what is ribonucleic acid (RNA)?
a special molecule that takes the code for amino acids from DNA to the ribosomes
what is messenger RNA (mRNA)?
an RNA molecule that transfers coded information from the nucleus to the ribosomes
what is transcription?
the process by which messenger RNA is formed, using the code in a DNA molecule by matching the sequence of nucleotides
what is RNA polymerase?
an enzyme that is active during transcription of RNA from DNA
