OCR (A) A+ LEVEL BIOLOGY .pdf OCR (A) A+ LEVEL BIOLOGY .pdf OCR (A) A+ LEVEL BIOLOGY .pdf
OCR (A) A+ LEVEL BIOLOGY
Water molecules consist of... - ANS-Two hydrogen atoms covalently bound to an
oxygen atom
Oxygen is more... (...), than hydrogen (...) - ANS-Electronegative (delta -ve), (delta +ve)
Hence, water is described as being... - ANS-Polar
As opposites attract, there is a force of attraction between... water molecules known as
a... - ANS-Different, Hydrogen bond
Name 6 biologically important properties of water. - ANS-Liquid medium, High specific
heat capacity, High latent heat of evaporation, Cohesive, Adhesive, Solvent
What is the significance of water being a 'liquid medium' ? (3 points) - ANS-It provides
habitat, It provides a site for chemical reactions, It is used in transport
What is the significance of water's 'high specific heat capacity' ? (in 2 environments) -
ANS-Helps maintain a stable temperature in aquatic and cellular environments
What is the significance of water's 'high latent heat of evaporation' ? (e.g.) -
ANS-Evaporation has a cooling effect e.g. through sweating
What is the significance of water being 'cohesive' ? (when moving up...) - ANS-Water
molecules 'stick' (cling) to each other when moving up the xylem
What is the significance of water being 'adhesive' ? (e.g.) - ANS-Water molecules are
attracted to (cling to) dissimilar substances e.g. the xylem wall
Water is a useful biological 'solvent'. This is because it can... (2 substances) -
ANS-Dissolve ionic and polar substances
Name the chemical elements that make up carbohydrates, lipids (+ steroids), proteins
and nucleic acids - ANS-Carbohydrates - C, H, O
Lipids (+ steroids) - C, H, O
Proteins - C, H, O, N, S
OCR (A) A+ LEVEL BIOLOGY .pdf OCR (A) A+ LEVEL BIOLOGY .pdf OCR (A) A+ LEVEL BIOLOGY .pdf
, OCR (A) A+ LEVEL BIOLOGY .pdf OCR (A) A+ LEVEL BIOLOGY .pdf OCR (A) A+ LEVEL BIOLOGY .pdf
Nucleic acids - C, H, O, N, P
Monosaccharides (also known as...) are... - ANS-Simple sugars, the simplest
carbohydrate
What is a hexose? - ANS-A monosaccharide with 6 carbon atoms
What is a pentose? - ANS-A monosaccharide with 5 carbon atoms
Describe the ring structure of alpha-glucose (C6 H12 O6) - ANS-- Oxygen atom
- C1: H up OH down
- C2: H up OH down
- C3: OH up H down
- C4: H up OH down
- C5: CH2OH up H down
Describe the ring structure of beta-glucose - ANS-- Oxygen atom
- C1: OH up H down
- C2: H up OH down
- C3: OH up H down
- C4: H up OH down
- C5: CH2OH up H down
Describe the ring structure of ribose - ANS-- Oxygen atom
- C1: H up OH down
- C2: H up OH down
- C3: H up OH down
- C4: CH2OH up H down
Disaccharides and polysaccharides are formed when... - ANS-Two or more
monosaccharides are joined in condensation
What is the bond between monosaccharides called? - ANS-Glycosidic bond
Disaccharides and polysaccharides are broken down into..., by... -
ANS-Monosaccharides, Hydrolysis
What two monosaccharides make up maltose? - ANS-Glucose + Glucose
OCR (A) A+ LEVEL BIOLOGY .pdf OCR (A) A+ LEVEL BIOLOGY .pdf OCR (A) A+ LEVEL BIOLOGY .pdf
OCR (A) A+ LEVEL BIOLOGY
Water molecules consist of... - ANS-Two hydrogen atoms covalently bound to an
oxygen atom
Oxygen is more... (...), than hydrogen (...) - ANS-Electronegative (delta -ve), (delta +ve)
Hence, water is described as being... - ANS-Polar
As opposites attract, there is a force of attraction between... water molecules known as
a... - ANS-Different, Hydrogen bond
Name 6 biologically important properties of water. - ANS-Liquid medium, High specific
heat capacity, High latent heat of evaporation, Cohesive, Adhesive, Solvent
What is the significance of water being a 'liquid medium' ? (3 points) - ANS-It provides
habitat, It provides a site for chemical reactions, It is used in transport
What is the significance of water's 'high specific heat capacity' ? (in 2 environments) -
ANS-Helps maintain a stable temperature in aquatic and cellular environments
What is the significance of water's 'high latent heat of evaporation' ? (e.g.) -
ANS-Evaporation has a cooling effect e.g. through sweating
What is the significance of water being 'cohesive' ? (when moving up...) - ANS-Water
molecules 'stick' (cling) to each other when moving up the xylem
What is the significance of water being 'adhesive' ? (e.g.) - ANS-Water molecules are
attracted to (cling to) dissimilar substances e.g. the xylem wall
Water is a useful biological 'solvent'. This is because it can... (2 substances) -
ANS-Dissolve ionic and polar substances
Name the chemical elements that make up carbohydrates, lipids (+ steroids), proteins
and nucleic acids - ANS-Carbohydrates - C, H, O
Lipids (+ steroids) - C, H, O
Proteins - C, H, O, N, S
OCR (A) A+ LEVEL BIOLOGY .pdf OCR (A) A+ LEVEL BIOLOGY .pdf OCR (A) A+ LEVEL BIOLOGY .pdf
, OCR (A) A+ LEVEL BIOLOGY .pdf OCR (A) A+ LEVEL BIOLOGY .pdf OCR (A) A+ LEVEL BIOLOGY .pdf
Nucleic acids - C, H, O, N, P
Monosaccharides (also known as...) are... - ANS-Simple sugars, the simplest
carbohydrate
What is a hexose? - ANS-A monosaccharide with 6 carbon atoms
What is a pentose? - ANS-A monosaccharide with 5 carbon atoms
Describe the ring structure of alpha-glucose (C6 H12 O6) - ANS-- Oxygen atom
- C1: H up OH down
- C2: H up OH down
- C3: OH up H down
- C4: H up OH down
- C5: CH2OH up H down
Describe the ring structure of beta-glucose - ANS-- Oxygen atom
- C1: OH up H down
- C2: H up OH down
- C3: OH up H down
- C4: H up OH down
- C5: CH2OH up H down
Describe the ring structure of ribose - ANS-- Oxygen atom
- C1: H up OH down
- C2: H up OH down
- C3: H up OH down
- C4: CH2OH up H down
Disaccharides and polysaccharides are formed when... - ANS-Two or more
monosaccharides are joined in condensation
What is the bond between monosaccharides called? - ANS-Glycosidic bond
Disaccharides and polysaccharides are broken down into..., by... -
ANS-Monosaccharides, Hydrolysis
What two monosaccharides make up maltose? - ANS-Glucose + Glucose
OCR (A) A+ LEVEL BIOLOGY .pdf OCR (A) A+ LEVEL BIOLOGY .pdf OCR (A) A+ LEVEL BIOLOGY .pdf
