biological elements Flashcards
(part of biological molecules)
what happens in an ionic bond?
- 1 atom in the pair donates an electron to another
- this forms 2 ions which are held together by that attraction of opposite charges
what are ions in solution called?
electrolytes
list 5 important cations!
- calcium ions
- sodium ions
- potassium ions
- hydrogen ions
- ammonium ions
list 5 important anions!
- nitrate ions
- hydrogen carbonate ions
- chloride ions
- phosphate ions
- hydroxide ions
what 2 things are calcium ions necessary for?
- nerve impulse transmission
- muscle contraction
what 2 things are Sodium ions necessary for?
- kidney function
- nerve impulse transmission
what 2 things are potassium ions necessary for?
- nerve impulse transmission
- stomatal opening
what 2 things are hydrogen ions necessary for?
- catalysis of reactions
- PH determination
what are ammonium ions necessary for?
production of nitrate ions by bacteria
what are nitrate ions necessary for?
nitrogen supply to plants for amino acid and protein formation
what are chloride ions necessary for?
balance positive charge of sodium and potassium ions in cells
what 3 things are phosphate ions necessary for?
- cell membrane formation
- nucleic acid and ATP formation
- bone formation
what 2 things are hydroxide ions necessary for?
- catalysis of reactions
- PH determination
which elements are present in carbohydrates?
carbon, hydrogen and oxygen
which elements are present in lipids?
carbon, hydrogen and oxygen
which elements are present in proteins?
carbon, hydrogen, nitrogen, oxygen and sulfur
which elements are present in nucleic acids?
carbon, hydrogen, nitrogen, oxygen and phosphorus
what are carbohydrates, lipids, proteins and nucleic acids all examples of?
biological molecules
what are polymers?
long-chain molecules made up of multiple linked monomers in a repeating pattern
what are the monomers in carbohydrates?
sugars (saccharides)
what are the monomers in proteins?
amino acids
explain how atoms join together to form molecules?
atoms form bonds with each other when pairs of electrons are shared
suggest why the x-ray diffraction technique used to produce the dna image wasn’t considered a form of microscopy. but the use of electrons to produce images is called electron microscopy? (3 marks)
- because x-ray diffraction doesn’t involve lenses
- electron microscope uses electromagnetic lenses
- beams are focused in electron microscopy to produce an image
explain why cells are visible with light microscopes but electron microscopes are needed to see ribosomes?
- cells are larger than ribosomes
- electron microscope has greater resolution than the light microscope
- molecules are smaller than resolution limit of light microscope and larger than resolution limit of electron beam.
