Carbohydrates Flashcards
Carbohydrates
A group of molecules containing C, H, O
What about monosaccharides make them good sources of energy?
Large number of carbon-hydrogen bonds
Maltose
Lactose
Sucrose
2 α-glucose
α + β
α + fructose
Condensation reaction removes water from…
2 hydroxyl groups (-OH)
Why are polysaccharides good stores of energy?
Less soluble because large + parts that could H bond are hidden
Chains branched so easily snipped off by hydrolysis when energy required
Branched so compact and don’t take up space
Cellulose properties/structure
Tough
Fibrous
Insoluble
long chains + straight
What prevents cellulose chains from spiralling?
Bonding
Every other β-glucose rotated
β 1-4 glycosidic bond
H bonds between molecules/chains give strength
Cell wall from…
Macrofibrils from microfibrils from
cellulose chains
Cell wall structure
Macrofibrils in all directions, criss-cross walls
Space between macrofibrils make wall permeable to water/mineral ions
Cell wall function
Prevents cells bursting when turgid
Difficult to digest
Support plant like skeleton (turgid cells press against each other)
Protect cell membrane
What prevents cells from bursting when turgid?
High tensile strength
From glycosidic and hydrogen bonds
Bacterial cell wall made from
Peptidoglycan
Long polysaccharide chains in parallel
Short peptide chains cross-link
glycosidic bond
bond formed between 2 monosaccharides by a condensation reaction
