sciecne revision

• ribosomes make proteins
• the nucleolus is where ribosomes are made
• the nucleus is the control center of the cell
• the nucleus is the control center of the cell, it contains DNA which controls all activities within the cell.
• mitochondria produce ATP through cellular respiration
• mitochondria produce energy through respiration
• chloroplasts contain chlorophyll, which absorbs light energy to convert it into chemical energy (ATP)
• the cytoplasm contains all the other parts of the cell, including the cytoskeleton (microtubules)
• chloroplasts are found only in plant cells and some protists; they contain chlorophyll and other pigments that absorb light energy needed to produce food by photosynthesis.
• mitochondria are responsible for producing ATP (energy) through aerobic respiration.
• chloroplasts contain chlorophyll to absorb light energy during photosynthesis
• chloroplasts contain chlorophyll which absorbs light to create glucose from carbon dioxide and water during photosynthesis
• the cytoplasm is the jelly-like substance that fills most of the cell
• vacuoles store water, waste products, pigments, or other substances
• the endoplasmic reticulum is a network of membranes involved in protein synthesis and lipid production
• cell membrane regulates what enters/exits the cell
• chloroplasts contain chlorophyll to absorb light energy from sunlight
• vacuoles store water or waste products
• the mitochondria is the powerhouse of the cell, it converts glucose into energy (ATP)
• chloroplasts contain chlorophyll, which absorbs light energy to convert it into chemical energy (ATP).
• chloroplasts convert light into chemical energy (glucose)
• vacuoles store water, waste products, or nutrients
• science: the systematic study of the structure and behaviour of the physical and natural world through observation, experimentation, and the testing of theories against the evidence obtained
• To view, download, or for more information, visit the Everything Science website on your phone or computer at www.everythingscience.co.za
• Scientific notation


  A way to write very large or very small numbers in the form N x 10^n, where N is a decimal number between 0 and 10 and n is an integer
• Physical quantity is anything that you can measure
• SI units


  The internationally agreed upon units, including base units like metre, kilogram, second, etc. and derived units like newton, joule, hertz, etc.
• Other systems of units

  • c.g.s. units
  • Imperial units
  • Natural units
• Combinations of SI base units can be assigned special names like newton, joule, hertz, etc.
• Prefixes of base units

  Prefixes like kilo, milli, micro, etc. that represent powers of 10 and are used with units
• Prefixes

  • yotta (Y)
  • zetta (Z)
  • exa (E)
  • peta (P)
  • tera (T)
  • giga (G)
  • mega (M)
  • kilo (k)
  • hecto (h)
  • deca (da)
  • deci (d)
  • centi (c)
  • milli (m)
  • micro (µ)
  • nano (n)
  • pico (p)
  • femto (f)
  • atto (a)
  • zepto (z)
  • yocto (y)
• There is no space and no dot between the prefix and the symbol for the unit
• Examples of using prefixes

  • 40 000 m can be written as 40 km (kilometre)
  • 0, 001 g is the same as 1 × 10−3 g and can be written as 1 mg (milligram)
  • 2, 5 × 106 N can be written as 2, 5 MN (meganewton)
  • 250 000 A can be written as 250 kA (kiloampere) or 0, 250 MA (megaampere)
  • 0, 000000075 s can be written as 75 ns (nanoseconds)
  • 3 × 10−7 mol can be rewritten as 0, 3 × 10−6 mol, which is the same as 0, 3 µmol (micromol)
• Without units much of our work as scientists would be meaningless
• Units give meaning to the numbers we measure and calculate
• Depending on which units we use, the numbers are different
• Units must be specified when expressing physical quantities
• Failure to convert English measures to metric values caused the loss of the Mars Climate Orbiter
• If you want to change kilometre to millimetre

  You multiply by 1000×1000
• To convert from km·h−1 to m·s−1

  You multiply by 1 000 and divide by 3 600