NECAP Science Reference Sheet “Your best friend during the NECAP Science Assessment”

Reference Sheet Formula Section

Reference Sheet Formula Section EquationVariables Each equation has its variables defined next to it

For example: The codon AAU represents the amino acid asparagine (Asp)asparagine The codon UGU and UGC represents and cysteine (Cys)cysteine The Genetic Code Table

How to Use the Genetic Code Table The genetic code is a set of rules, which maps DNA sequences to proteins in the living cell through the mechanism of protein synthesis. Nearly all living things use the same genetic code, called the standard genetic code, and all use small variations of it.mapDNA sequenceproteincellprotein synthesis –The code is represented by an immensely long polymeric molecule, Deoxyribonucleic Acid ( DNA), and each functional portion of this molecule is referred to as a gene. Each gene is transcribed into a short template for protein synthesis, Ribonucleic Acid ( RNA), which is in turn translated into an amino acid chain ( polypeptide). The gene sequence is composed of units called codons, each coding for an amino acid, hence the phrase ‘genetic code’. The polypeptide is ultimately folded into a 3-dimensional protein structure, which will go on to perform some specific function in the cell such as an enzyme subunit or cell membrane component. DNAgeneRNAamino acidpolypeptideproteinenzymecell membrane –This chain of events involving RNA transcription, and polypeptide translation is referred to as gene expression. Some genes encode other elements such as ribosomal RNAs and transfer RNAs, both of which are involved in protein synthesis. gene expressionribosomal RNAstransfer RNAs Both DNA and RNA are comprised of 4 nucleotide bases:nucleotide –DNA: adenine, guanine, cytosine and thymineadenineguaninecytosinethymine –RNA: adenine, guanine, cytosine and uraciluracil Codons are non-overlapping groups of the three bases. There are 43 = 64 codons. For example, the RNA sequence UUUAAACCC contains the codons UUU, AAA and CCC, each of which specifies one amino acid. So, this RNA sequence represents a protein sequence, three amino acids long. ( DNA is also a sequence of nucleotide bases, but there thymine takes the place of uracil.)DNAthymine The standard genetic code is shown in the following tables. Table 1 shows what amino acid each of the 64 codons specifies. Table 2 shows what codons specify each of the 20 standard amino acids involved in translation. These are called forward and reverse codon tables, respectively. For example, the codon AAU represents the amino acid asparagine (Asp), and cysteine (Cys) is represented by UGU and by UGC.asparaginecysteine

The Electromagnetic Spectrum

Electromagnetic Waves. –Transfer energy from a source as waves All electromagnetic waves travel at the speed of light. –300,000,000 m/s = 3 × 10 8 m/s All waves have a frequency. –This means the number of waves per second. –Frequency is measured in Hertz (Hz). All waves have a wavelength. –This is the length of one complete wave, the distance between two successive peaks. –Wavelength is measured in meters (m). From the chart as the Frequency gets lower, the Wavelength gets longer.

Tectonic Plate Boundaries

There are four types of plate boundaries: –Divergent Boundaries Plates move away from each other New crust is generated –Convergent Boundaries Plates move toward each other Crust is destroyed as one plate dives under another. –The location where sinking of a plate occurs is called a subduction zone. –Transform Boundaries Plates slide past each other Crust is neither produced nor destroyed –Plate Boundary Zones Broad belts in which boundaries are not well defined Effects of plate interaction are unclear

The Periodic Table of Elements Elements are arranged left to right and top to bottom in order of increasing atomic number The Table's pattern and arrangement shows the arrangement of electrons in the atom. –Elements have different atomic numbers - the number of protons or electrons increases up the table as electrons fill the shells. –Elements have different atomic masses - the number of protons plus neutrons increases up the table. Rows - elements of each row have the same number of energy levels (shells). Columns - elements have the same number of electrons in the outermost energy level or shell (one to eight).

The Periodic Table The different rows of elements are called periods. –The period number of an element signifies the highest energy level an electron in that element occupies The different columns of elements are called groups or families –Elements in the same family have similar properties

How to read the periodic table: Every table has:

How to read the periodic table: Atomic Number The number of protons in an atom identifies the element. The number of protons in an atom is referred to as the atomic number of that element.

How to read the periodic table: Atomic Mass: The atomic mass is the average mass of an element in atomic mass units ("amu"). Though individual atoms always have a whole number of amus, the atomic mass on the periodic table is shown as a decimal number because it is an average of all the isotopes of an element.

How to read the periodic table: Atomic Symbol: The atomic symbol is one or two letters chosen to represent an element ("H" for "hydrogen," etc.). These symbols are used every where in the world Usually, a symbol is the abbreviation of the element or the abbreviated Latin name of the element.