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NECAP Science
Reference Sheet
“Your best friend during the
NECAP Science Assessment”
Reference Sheet
Formula
Section
Reference Sheet Formula Section
Equation Variables
•Each equation has its
variables defined next to it
The Genetic Code Table
For example:
The codon AAU represents the amino acid asparagine (Asp)
The codon UGU and UGC represents and cysteine (Cys)
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.
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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.
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.
•
Both DNA and RNA are comprised of 4 nucleotide bases:
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DNA: adenine, guanine, cytosine and thymine
RNA: adenine, guanine, cytosine and uracil
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.)
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.
The Electromagnetic Spectrum
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 × 108 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
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.