Chapter 16: The Molecular Basis of Inheritance Flashcards
Hereditable Factors:
Mendel’s word for “genes”, factors that are passed on from generations.
What is a chromosome?
A chromosome is a thread-like structure made up of DNA and proteins.
What are histones?
Proteins that help package and organize DNA into structural units called nucleosomes.
What is chromatin?
A complex of DNA and proteins (histones) found in the nucleus of eukaryotic cells that makes up chromosomes. It efficiently packages longer DNA strands into compact, organized structures that fit in the nucleus.
Explain euchromatin vs heterochromatin.
Euchromatin: The less condensed form of chromatin that is available for transcription.
Heterochromatin: The highly compacted form of chromatin that remains tightly packed during interphase and is not generally transcribed.
Define antiparallel (complementary)
Refers to the orientation of the two strands in a DNA double helix, where one stand runs in the opposite direction to the other.
What is a base pair?
The unit that the size of DNA is measured in. To find this number, count the two nitrogenous bases paired together in a DNA molecule (A+T, C+G)
What is the DNA backbone?
The phosphate groups that make up the sugar-phosphate backbone, providing structural support and stability to the double helix structure of DNA. The DNA backbone has a negative charge, giving DNA its overall negative charge.
List some differences between DNA and RNA.
DNA:
- double stranded
- missing an oxygen atom in its sugar
- nitrogenous bases include adenine, thymine, cytosine, and guanine
- DNA are genes
RNA:
- single stranded
- nitrogenous bases include adenine, guanine, cytosine, and uracil
- functions include copying and delivering messages encoded in DNA
List some enzymes and proteins needed to carry out the DNA cycle and their functions.
- DNA Polymerase (I and III) - the enzyme that catalyzes the addition of nucleotides to the growing DNA strand during DNA replication. Ideal temp is 37 degrees celcius.
