Use the Nelson text, "Biology 11", pp. 45-47 to complete the blanks.

* NUCLEIC ACIDS *

The two nucleic acids, __________ and ___________ are not nutrients but are essential for living things.

DNA consists of:
1) ____________________________________ (called deoxyribose)
2) ____________________________________
3) ____________________________________

Nitrogenous bases:
A: _________________________
G: _________________________
C: _________________________
T: _________________________ (RNA has _________________ instead of Thymine).

The basic building block of DNA is the _________________________ which consists of a sugar, base, and phosphate group. So a DNA molecule has thousands of _______________________ joined together.

DNA exists as two helical strands wrapped around each other to make a _________________ ______________. One strand is bonded to the other by the _________________________ bases.

A binds with _____ and C binds with __________. This is called "_________________________ base pairing".

Draw Fig. 1 on pg. 46

In Eukaryotic cells, DNA is found in the ______________________________ in the nucleus. The order or the bases genetically determines the order of _________________ ______________ in a protein. Thus, each protein is coded for by a stretch of bases called a _____________. This is referred to as the "one gene, one protein" hypothesis. If you change the order of bases in DNA (a genetic ___________________), the protein will usually not be functional. This can cause genetic disease.

Each amino acid is coded for by not one but __________ bases in DNA. Because each DNA molecule has thousands of nucleotides (thus bases), a single DNA can contain many ____________ and thus produce many ________________________.

Protein Synthesis (see Fig. 1 on pg. 41 from Protein sheet):

1. DNA codes for a sequence of amino acids that will make up a protein. This code is copied to a molecule called __________ (messenger RNA). This step is called TRANSCRIPTION.


2. mRNA leaves the nucleus and enters the _____________________ where it attaches to a ________________________ on the ER.


3. Each amino acid coded for by the mRNA is brought to the ribosome by ______________ (transfer RNA).


4. The amino acids delivered by tRNA are strung together in the correct order to make a complete ______________________. This step is called TRANSLATION.


5. The complete protein is inserted into the ER for transport to the ______________________ where it is packaged.