Biochemical Foundations of Medicine Flashcards
Levels of organization of an organism? (5)
Organism, organ, cell, organelle, biomolecules
Parts of a cell (9)
Plasma membrane, endoplasmic reticulum, nucleus, cytoplasm, cytoskeleton, ribosomes, mitochondrion, lysosome, golgi body
What are simple molecules.
H20, CO2, NH3, O2, N2
What are the cellular building blocks?
amino acids, carbohydrates, nucleotides, lipids
What are the polymers?
Proteins (amino acid polymers), polysaccharides (carbohydrate polymers), nucleic acids (nucleotides)
What are supra-molecular assemblies
ribosomes, chromatin, membranes
What are lipids used to build?
Not polymerized but aggregated into supra-molecular assemblies (no covalent bonds)
What are the identifying features of amino acids?
- an alpha carbon atom with a hydrogen atom, a carboxylic acid and an amino group
- side chain (R-group) - varies
What are the identifying features of carbohydrates?
C(H20), linear or cyclic form, every carbon has a h20 attached to it
What are the identifying features of nucleotides?
- Nitrogenous base (aromatic)
- Sugar
- Inorganic phosphate (mono, di or tri)
What are the identifying feature of lipids?
Hydrocarbons, mainly contain hydrogen or carbon, may be aromatic or linear
What is the defining feature of an unsaturated lipid?
contains carbon carbon double bounds (room for more H’s)
What does residue refer to?
What’s left of a monomer in a polymer, water is lost,
How are polymers attached (polymer)?
via covalent bounds
Amino acids are linked by _____ to form _____ (___)
peptide bounds, polypeptides, proteins
Nucleotides are linked by _____ to form _____ (___)
phosphodiester bonds, nucleic acids, (RNA, DNA)
Monosaccarides are linked by _____ to form _____ (___)
glycosidic bonds, polysaccharides, (starch, glycogen, cellulose)
What is a primary structure?
a biopolymer’s primary structure is the sequence of monomers linked by covalent bounds
What are the secondary and tertiary structures?
Higher levels of structure of bipolymers depending entirely on non-covalent bounds between atoms
What are hydrogen bonds?
Special dipole-dipole interaction (since the dipole is permanent) which involve an H atom attached to a more electronegative atom such as O or N.
What are salt bridges?
biological molecules contain numerous organic functional groups which are constitutively charged at physiologic pH and can thus make ionic interactions with one another
How many hydrogen bounds are possible per water molecules?
4, 2 donors and 2 acceptors
Water is highly….
cohesive
What kind of structure does ice have?
a crystalline lattice structure
Water molecules behave in a way that…? what does this result in?
maximizes their interaction with each other (maximum entropy) at any time resulting in the hydrophobic effect.
What do proteins do (5)?
EVERYTHING!! Structure - connective tissue Movement - muscle Catalysis - enzymes (metabolism) Transport - Hb-O2, across cell membranes Communication - receptors and signalling
What determines the function of a protein?
Its structure
What are the two main classes of protein structure?
Globular or fibrous
What is a globular protein?
proteins folded into a spherical (globular) shape. The can be enzymes, transporter proteins, receptors
What is a fibrous protein?
Protein formed into filaments and are usually used to construct connective tissue, tendons, bone, matrix and muscle fiber
What are the two major purposes of metabolism?
obtain usable chemical energy from the environment, make specific molecules that cells need to live and grow
What are the two major types of metabolic pathways?
Catabolic, anabolic
What are the catabolic pathways?
Break down complex molecules (FUELS) to more simple metabolic intermediates and ultimately, CO2 and H2O; Extract and harness usable chemical energy (ATP) from chemical bonds: are Oxidative - remove electrons from molecules
What are the anabolic pathways?
Build complex molecules from simple precursors; require the input of chemical energy (ATP) to build new chemical bonds; are reductive – require electrons to make chemical bonds
How many metabolic reaction occur in the human body?
over 500
All metabolic pathways obey the same _______
fundamental principles
Not all reactions occur in every ______ and not all reactions occur in every ______
organism, celll
What is a metabolic pathway?
a series of consecutive, enzyme-catalyzed reactions producing a specific product from a specific starting metabolite
How are the metabolic intermediates maintained at a steady level?
- irreversible reactions (rate-limiting reactions) – the enzymes that catalyze these are tightly regulated
- Reversible reactions - direction depends on concentration of intermediates – enzymes are not regulated
What are the three major fuels for cellular catabolism? What are these broken down into?
proteins, carbs, lipids
Acetyl-CoA
What does acetyl-CoA feed into?
the citric acid cycle, and is broken down to CO2
Where are electrons from Acetyl-CoA
Electrons from the acetyl-CoA are “saved” in electron carriers (enzyme cofactors) - NADH and FADH2
Where are the reduced electron carriers re-oxidized and what does this require? What is the energy of the electrons used to produce?
via the electron transport chain, oxygen (which is converted into water), ATP
What maintains fuel molecules in the blood stream?
the liver
What transports fuel molecules to the liver?
the hepatic portal vein
How does the liver process fuel molecules (3)?
- Catabolism (immediate energy needs of hepatocytes)
- Storage of excess fuel molecules
- Processing/release into the blood stream for other organs/tissues
How and where is glucose stored?
As glycogen in the liver and skeletal muscle
How and where are fatty acids stored?
as fat (triacylglcerols) in adipocytes
What are the two types of organ specialization in metabolism?
Fuel Users and Fuel providers
What kind of fuel does the brain use?
Obligatory glucose user –> will switch to ketones if necessary
The liver maintains ______ in the blood for the use of all other tissues
suitable levels of fuel molecules
How does the liver maintain suitable levels of fuel molecules?
Using it’s own glycogen stores –> glucose, Fatty acids from food or tissue –> ketone bodies, (sometimes amino acids –> glucose)
What is the primary function of adipose tissue
long-term storage of energy
