Module 2 Section 2 - Biological Molecules Flashcards
Smithson
2 biological molecules people often forget about
- nucleic acids
- inorganic ions (don’t contain carbon)
Which charge does the oxygen atom in a water molecule have?
A partial/slightly negative charge.
What charge do the hydrogen atoms in a water molecule have?
A partial/slightly positive charge.
δ+
delta positive - positive charge
Explain why water can form hydrogen bonds. [1]
Water molecule is polar/as electrons are pulled closer to the oxygen atom
cohesion
The force of attraction between water molecules which makes them stick to each other
adhesion meaning
two different molecules stick together (e.g. water and a surface)
Describe the process of adhesion in plants.
When water molecules are attracted to the impermeable walls of xylem tissue.
Adhesion is the force of attraction between water and surfaces it is in contact with. This makes water molecules stick to other things.
Water molecules are attracted to the ____ walls of ____ tissue.
impermeable, xylem
Explain water’s SHC and the benefit of this.
High SHC due to the hydrogen bonds as they absorb lots of energy. This means water doesn’t experience fast temperature changes, so makes it a good habitat - the temperature is less variable than on land.
Explain water’s SLH and the benefit of this.
Takes a lot of energy to break the hydrogen bonds between molecules so a lot of energy is used when water evaporates. This means water is good as a coolant i.e. sweat.
Explain water’s density and the benefit of this.
Water molecules are held further apart in ice than when liquid as the molecules form a regular lattice with gaps (not air) between the molecules, making ice less dense than when liquid.
In cold temperatures, an insulating layer is formed on the top of the body of water, preventing the water beneath from freezing. This conserves the habitat and organisms don’t freeze, allowing them to continue to move around.
Explain water’s polarity and the benefit of this.
The slightly positive end attracts to the negative ion and the slightly negative end attracts to the positive ion. This means the ions become completely surrounded by water molecules, allowing them to dissolve (water is a useful solvent e.g. for transport of ions).
Why is the ability of water to act as a solvent (excluding transport) important for the survival of organisms? (3)
- Organisms can take in ions
- Water is a medium for reactions [1] because it allows ionic compounds to separate [1]
- Water can dilute toxic substances
5 biological functions of water
- solvent
- transport
- habitat
- reactant in chemical reactions
- aids temperature control (coolant)
What does a diagram of ice look like?
Lattice shape
Lots of air space between water molecules
enzyme cofactor
A non-protein inorganic substance that helps an enzyme to function
How is calcium involved in
biological processes? (4)
- helps transmit electrical impulses
- helps release insulin from the pancreas
- acts as a cofactor for many enzymes e.g. blood clots
- important to form bones
BIIC
How is sodium involved in
biological processes? (3)
- helps muscles to contract
- important to produce nerve impulses
- helps to regulate fluid balance (e.g. keeping plant cells turgid)
For all three, sodium works closely with potassium
How is potassium involved in
biological processes? (4)
- helps muscles to contract
- important to produce nerve impulses
- helps to regulate fluid balance (e.g. keeping plant cells turgid)
- activates enzymes for photosynthesis in plant cells
For the top three, potassium works closely with sodium
How is ammonium involved in
biological processes? (1)
Source of nitrogen (used to make amino acids, nucleic acids etc.)
How is hydrogen involved in
biological processes? (2)
- important for respiration reactions in mitochondria & inner membrane and photosynthetic reactions in thylakoid membranes
- affects substances’ pHs
The top function is similar to one of PO43-’s functions
How is nitrogen involved in
biological processes? (1)
Source of nitrogen (used to make amino acids, nucleic acids etc.)
How is hydrogencarbonate involved in
biological processes? (1)
acts as a pH buffer (which resists pH change) to maintain the pH of the blood