biological elements

Question 1

what happens in an ionic bond?

Answer 1

• 1 atom in the pair donates an electron to another

- this forms 2 ions which are held together by that attraction of opposite charges

Question 2

what are ions in solution called?

Answer 2

electrolytes

Question 3

list 5 important cations!

Answer 3

• calcium ions
• sodium ions
• potassium ions
• hydrogen ions
• ammonium ions

Question 4

list 5 important anions!

Answer 4

• nitrate ions
• hydrogen carbonate ions
• chloride ions
• phosphate ions
• hydroxide ions

Question 5

what 2 things are calcium ions necessary for?

Answer 5

• nerve impulse transmission

- muscle contraction

Question 6

what 2 things are Sodium ions necessary for?

Answer 6

• kidney function

- nerve impulse transmission

Question 7

what 2 things are potassium ions necessary for?

Answer 7

• nerve impulse transmission

- stomatal opening

Question 8

what 2 things are hydrogen ions necessary for?

Answer 8

• catalysis of reactions

- PH determination

Question 9

what are ammonium ions necessary for?

Answer 9

production of nitrate ions by bacteria

Question 10

what are nitrate ions necessary for?

Answer 10

nitrogen supply to plants for amino acid and protein formation

Question 11

what are chloride ions necessary for?

Answer 11

balance positive charge of sodium and potassium ions in cells

Question 12

what 3 things are phosphate ions necessary for?

Answer 12

• cell membrane formation
• nucleic acid and ATP formation
• bone formation

Question 13

what 2 things are hydroxide ions necessary for?

Answer 13

• catalysis of reactions

- PH determination

Question 14

which elements are present in carbohydrates?

Answer 14

carbon, hydrogen and oxygen

Question 15

which elements are present in lipids?

Answer 15

carbon, hydrogen and oxygen

Question 16

which elements are present in proteins?

Answer 16

carbon, hydrogen, nitrogen, oxygen and sulfur

Question 17

which elements are present in nucleic acids?

Answer 17

carbon, hydrogen, nitrogen, oxygen and phosphorus

Question 18

what are carbohydrates, lipids, proteins and nucleic acids all examples of?

Answer 18

biological molecules

Question 19

what are polymers?

Answer 19

long-chain molecules made up of multiple linked monomers in a repeating pattern

Question 20

what are the monomers in carbohydrates?

Answer 20

sugars (saccharides)

Question 21

what are the monomers in proteins?

Answer 21

amino acids

Question 22

explain how atoms join together to form molecules?

Answer 22

atoms form bonds with each other when pairs of electrons are shared

Question 23

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)

Answer 23

• because x-ray diffraction doesn’t involve lenses
• electron microscope uses electromagnetic lenses
• beams are focused in electron microscopy to produce an image

Question 24

explain why cells are visible with light microscopes but electron microscopes are needed to see ribosomes?

Answer 24

• 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.