Molecules of the Cell (week one) Flashcards
(25 cards)
what are the four classes of molecules?
carbohydrate, lipid, protein, nucleic acids
polymer formation occurs through:
condensation (dehydration - water is freed)
polymers are broken apart through:
hydrolysis (water is consumed)
what are polysaccharides (carbs) made up of?
monosaccharides
what are the functions of carbohydrates?
stored short term energy and used in cellular respiration
what are the functions of lipids?
stored long term energy, insulation, protection, cell membrane
what are the functions of proteins?
structured support, channels, receptors, enzymes
what are the functions of nucleic acids?
DNA, RNA - instructions within our cells
which of the 4 macromolecules isn’t a polymer?
Lipids
what are some common polysaccharides?
starch, glycogen, cellulose, chitin
what is the monomer of protein?
amino acids
what occurs in the primary structure of proteins?
sequence of amino acids; stabilized by peptide bonds
what occurs in the secondary structure of proteins?
caused by hydrogen bonds occurring at amino acids at different points in the sequence (alpha or beta sheets); (R-GROUPS ARE NOT INVOLVED)
what occurs in the tertiary structure of proteins?
controlled by R groups; if they’re hydrophilic, they ago outside and if hydrophobic, they sit on inside of protein to avoid water (usually 3-dimensional shape)
what occurs in the quaternary structure of proteins?
subunits come together (2 separate sequences of amino acids) interacting at their R groups; stabilized by bonds/interactions between R-groups and peptide-bonded backbone
saturated fats are solids because?
acid tails are pin straight allowing for many to pack together tightly
unsaturated fats are liquid because?
one of the acid tails has a double bond, which creates a kink (prevents them from packing close together)
we describe phospholipids as amphipathic. what does this mean?
a substance has both hydrophilic and hydrophobic parts (phospholipid bilayer - polar/hydrophilic head, non polar/hydrophobic tail)
how are proteins in secondary structure stabilized?
polar interactions between the protein and backbone
what is denaturation?
changes in the environment and chemical interactions can alter protein shape.
what are steroids?
lipids with extensive ring structures that are found in the cell membrane
how do plants store energy?
as sugars (less energy per gram put easier to make/access)
how do animals store energy?
as lipids (more energy per gram)
what is our main molecule of energy?
ATP
