Biochemistry A Flashcards
Metabolism
An organism’s net sum of reactions, the result of enzyme catalyzed biological pathways
Catabolic Reactions
Breaking down complex polymers into monomers, releases energy
Anabolic Reactions
Monomers are synthesized to form a polymer, requires energy
Examples of Anabolic Reactions
Photosynthesis, DNA replication, protein synthesis
Condensation Reaction (Dehydration Synthesis)
Two molecules covalently bonded to each other through the loss of water
Hydrolysis Reaction
A covalent bond is broken through the addition of water
Carbohydrates
Carbon, hydrogen and oxygen in a specific ratio. Categorized as monosaccharides, disaccharides and polysaccharides.
Carbohydrates Functions (2)
Provide energy storage and building blocks of life
Prefix in front of -ose indicates…
Number of carbon atoms in each molecule, e.g. triose has three carbon molecules
Monossacharides
Simple ring shaped sugar molecule, basic unit of carbohydrates
Isomers
Have the same formula but are structurally different, e.g. glucose, fructose and galactose
DIssacharides
2 monosaccharides bonded by a glycosidic bond
Sucrose
Fructose + glucose
Lactose
Galactose + glucose
Maltose
2 glucose molecules
Polyssacharides
Long chains of three or more monosaccharides
Starch in plants and glycogen in animals are responsible for …
Energy storage
Cellulose in plants and chitin in fungi and arthropods are responsible for forming…
Structure
Cellulose
Plant source, beta glucose subunit, 1 - 4 bonding, no branching
Starch: amylose
Plant source, alpha glucose subunit, 1 - 4 bonding, no branching
Starch: amylopectin
Plant source, alpha glucose subunit, 1 - 4 and 6 bonding, branching evry 20 subunits
Glycogen
Animal source, alpha glucose subunit, 1 - 4 and 6 bonding, branching every 10 subunits
Lipids
Carbon, hydrogen and oxygen atoms in an unfixed ratio. Can be phospholipids, triglycerides, steroids, and waxes.
Types of Lipids
Phospholipids (only lipid that contains phosphorus), e.g. lecithin, plasma membrane structure
Triglycerides: fats, oils, long term energy storage
Steroids: cholesterol, testosterone and estrogen: membrane component and sex hormones
Waxes: cuticle: protective covering
Five functions of lipids
Cell membrane component, long term energy storage, insulation, organ cushioning, structural component of hormones
Structure of a triglyceride
1 glycerol molecule, fatty acid chains
Ester Linkage
Binds the glycerol molecule to the hydrocarbon chains
Lipids are differentiated based on the level of…
Hydration of the carbon atoms in the fatty acid chain
Saturated Lipids
All carbons have the maximum number of hydrogen atoms
Monounsaturated
Only one double bond between carbons
Polyunsaturated
More than one double bond
Why are saturated lipids less healthy than unsaturated lipids?
Saturated lipids are harder to break down and absorb because they tend to be solid at room temperature by forming London dispersion forces that are difficult to break apart completely. The bends in unsaturated lipids help membrane fluidity and prevent stacking
Hydrogenation
Make a lipid more solid (creation of saturated lipids)
Cis vs trans fats
Cis lipids have hydrogens on the same size, causing kinks. Trans fats have hydrogens on opposing sides, resulting in a linear chain.
Why are trans fats desirable?
They are more stable at higher temepratures, last longer and taste better