Topic 1.1 Chemistry for life Flashcards
The role of nitrate ions in plants
-Proteins
-DNA
-Amino acids
-NADP for photosynthesis
-NAD for respiration
Proteins promote growth.
The role of calcium ions in plants
Used to make calcium pectate, which adds stability to the middle lamella of cell wall
(layer that joins adjacent cells).
The role of magnesium ions in plants
Component of chlorophyll, which absorbs light energy for photosynthesis.
The role of phosphate ions in plants
Component of:
-ADP and ATP which are involved in energy release for metabolic reactions
-NADP for photosynthesis
5 biologically important properties of water
-Reaches maximum density at 4°C
-High specific heat capacity
-High surface tension
-Acts as polar solvent
-Incompressible
Why do water molecules have a permanent dipole?
O is more electronegative than H, so attracts the electron density in the covalent bond more strongly.
Forms Oδ- (slight negative charge) and Hδ+ (slight positive charge).
Intermolecular bonding between water molecules
Hydrogen bonds form between lone pair on O of one molecule and Hδ+ on neighbouring molecule.
Why is the high specific heat capacity of water important for organisms?
Acts as a temperature buffer which enables endotherms to resist fluctuations in core temperature to maintain optimum enzymes activity.
Why is water important solvent for organisms?
Polar universal solvent dissolves and transports charged particles involved in intra and extracellular reactions.
Why is the high surface tension of water importance for organisms?
-Sloggers water loss due to transpiration in plants.
-Water rises unusually high in narrow tubes, lowering demand on root pressure.
-Some insects can ‘skim’ across the surface of water.
Why is the incompressible nature of water important for organisms?
-Provides turgidity to plant cells
-Provides hydrostatic skeleton for some small animals eg. earthworms.
Why does ice float on water and why is this important for organisms?
Ice is less dense than water because H- bonds hole molecules in fixed positions further away from each other.
Insulates water in arctic climates so aquatic organisms can survive.
Important anions: Nitrate ions (NO3-)
Needed in plants; combines with glucose to form amino acids and therefore proteins fro growth, also for the formation of DNA.
Important anions: Phosphate ions (PO4^3-)
Needed in all living organisms in the formation of ATP and ADP and in DNA and RNA.
Important anions: Chloride ions (Cl-)
Needed in nerve impulses and many secretory systems.
