biological molecules

• The three-dimensional structure of proteins is determined by the sequence of amino acids.
• The four types of macromolecules

  carbohydrates, lipids, proteins and nucleic acids
• all macromolecules

  contain:

  Carbon hydrogen and oxygen
• Nitrogen appears in which macromolecule

  proteins and nucleic acids
• what is metabolism 


  The enzymatic reactions that take place inside a living organism
• what is anabolism?

  is the synthesis of complex molecules from simpler molecules
• what is catabolism?


  Breakdown of complex molecules into simpler ones to release energy.
• what is hydrolysis

  the breaking of a chemical bond by the addition of water molecules
• what is a condensation reaction 


  refers to the reaction in which two smaller organic molecules combine to form a larger molecule with the accompanied formation of water or some other simple molecule.
• metabolism =

  anabolism + catabolism
• What is urea

  Organic compound with the formula CO(NH2)2
• what is urea used for?

  It is used by the human body to excrete nitrogen because urea is non -toxic and highly soluble
• what is the make-up of water?

  2 hydrogen atoms and 1 oxygen atoms
• structure of water 


  is:

  
• why are water molecules polar?

  due to their dual nature, they have both positive and negative charges
• what does waters dual nature allow?

  the formations of hydrogen bonds between water molecules
• what is hydrophillic

  water loving
• what is hydrophobic?

  water repelling
• what does the polarity of water allow?

  it allows them to attract other polar or charged compounds and form hydrogen bonds with the, most polar or charged compounds can be dissolved in water
• examples of non polar substances

  oils and fats
• what is cohesion related to water?

  the tendency of water molecules to stick to each otherdue to hydrogen bonding between them
• what is surface tension related to water?

  due to hydrogen bonding of water molecules, makes the water surface behave as a strong elastic membrane
• surface tension is also responsible for

  water droplets adopting a spherical shape minimising the ratio of area to volume
• what is adhesion?

  the interaction that water molecules have with other different molecules
• what is capillary action?

  the movement of water molecules and all the things that are dissolved in it.
• what are the thermal properties of water?

  the hydrogen bonds that hold water molecules together are responsible for the the unique e.g. the high specific heat capacity = to break down water lots of thermal energy is needed.
• water is a solvent because ?

  it can dissolve ionic compounds as well as many polar compounds, such as glucose
• what is glucose?

  polar molecule, soluble in water so it can be transported in the blood,
• what are amino acids

  both negatively and positively charged. Most are soluble in water. Their solubility is based on their R group
• if amino acids had a hydrophilic R group they are easily dissolved in water
• if amino acids have a hydrophobic R- group they will not be easily dissolved in water
• what are the properties of fats
• what are the properties of fats

  they are non polar they are insoluble in water and are transported by lipoproteins.
• what are the properties of cholesterol?

  is required for synthesis of many biologically important molecules and it is the component of membranes. It requires the help of transport lipoproteins because it is hydrophobic
• what are the properties of sodium chloride?

  an ionic compound, it's transported in the blood in the form of Na+ and Cl- ions they are easily dissolved in water
• what are the properties of water?

  non polar, but because it is small, it is soluble in water to a limited extent
• thermal properties of water?

  liquid at room temp, polar, excellent solvent, boiling temp 100 degrees, melting point 0 degrees,
• thermal properties of methane?

  gas at room temp, non polar not a solvent, boiling point -161 degrees, melting point -182 degrees
• monosaccharides and disaccharides are considered sugars which are polar and soluble in water