Nucleic Acids Flashcards
what are molecules?
molecules → make up → gentic material → all living things
“building blocks of life”
what is a nucleotide?
A nucleotide is the basic building block of nucleic acids (RNA and DNA). A nucleotide consists of a sugar molecule (either ribose in RNA or deoxyribose in DNA) attached to a phosphate group and a nitrogen-containing base.
what his a nucleotide made up of?
phosphate, sugar, nitrogenous bases
what are the two types of nucleic acids?
- DNA (deoxyribonucleic acid)
- RNA (ribonucleic Acid)
what is the purpose of sugar in a nucleotide?
the sugar creates a strong bond with phosphate, creating the sugar-phosphate backbone
what is the purpose of nitrogen bases in a nucleotide?
the nitrogen base projects off the sugar to create a site ready for binding
What is condensation polymeriastion?
It is a form of a step-growth polymerization where smaller molecules or monomers react with each other to form larger structural units (usually polymers) while releasing by-products such as water or methanol molecule.
how are the four bases bonded?
bases are bonded using a weak hydrogen bond
what are the four bases?
Cytosine, Guanine, Adenine, thymine Uracil ( only for RNA)
What are the two base pairs
1) AT Adenine, thymine
2) GC Cytosine, Guanine
Where is the base Uracil found?
RNA strand
Because DNA is like a long piece of very fine string, it is important it doesn’t tangle or break. In order to keep the DNA from tangling, a molecule called a ______ is used.
nucleosome
what is a nucleosome?
A nucleosome is compromised of 8 proteins called histones which clump together. DNA wrap 1 3/4 times around these histones, providing order and structural integrit. (meaning doesn’t tangle of break.
what is a histone?
A type of protein found in chromosomes. Histones bind to DNA, help give chromosomes their shape, and help control the activity of genes.
what is DNA
DNA is the collection of nucleotides that makes up genes and chromosomes.
What are Genes?
- Genes are segments of DNA that tell the body how to express (show) something.
- For example, there is a gene that tells your body what colour to make the iris in your eyes. (There’s actually a few genes which do this).
What are chromosomes?
- A chromosome is made up of the entire strand of DNA, which is comprised of many genes. So a chromosome is represented by the entire image to the right.
- In nature there are two main types of chromosomes: prokaryotic chromosomes and eukaryotic chromosomes.
what are prokaryotic chromosomes?
- Prokaryotes do NOT have a nucleus. So instead of having their chromosomes encased inside of a nucleus, they have a single chromosome which floats freely around the cell.
- Prokaryotic DNA is:
- Circular, double stranded
- Not bound to histone proteins
mitochondrail and chloroplast DNA
- Mitochondria and Chloroplasts also have genetic material stored within them.
- The DNA found in these organelles is very similar to prokaryotic DNA and supports the theory of endosymbiosis (the idea that mitochrondria was taken into another cell in a mutualistic relationship)
what are eukaryotic chromosomes?
- Eukaryotic chromosomes are located in the nucleus and are mostly found in pairs. (There are some species which are exceptions).
- In humans (and many plants and animals) chromosomes are passed on to offspring via sexual reproduction.
- In this case, one set of the pair of chromosomes comes from the father and the other from the mother.
- So one ‘Chromosome 1’ (see left) comes from Dad and the other comes from Mum- it is the same for the other 22.
