Biochemical Foundations of Medicine

Question 1

Levels of organization of an organism? (5)

Answer 1

Organism, organ, cell, organelle, biomolecules

Question 2

Parts of a cell (9)

Answer 2

Plasma membrane, endoplasmic reticulum, nucleus, cytoplasm, cytoskeleton, ribosomes, mitochondrion, lysosome, golgi body

Question 3

What are simple molecules.

Answer 3

H20, CO2, NH3, O2, N2

Question 4

What are the cellular building blocks?

Answer 4

amino acids, carbohydrates, nucleotides, lipids

Question 5

What are the polymers?

Answer 5

Proteins (amino acid polymers), polysaccharides (carbohydrate polymers), nucleic acids (nucleotides)

Question 6

What are supra-molecular assemblies

Answer 6

ribosomes, chromatin, membranes

Question 7

What are lipids used to build?

Answer 7

Not polymerized but aggregated into supra-molecular assemblies (no covalent bonds)

Question 8

What are the identifying features of amino acids?

Answer 8

• an alpha carbon atom with a hydrogen atom, a carboxylic acid and an amino group
• side chain (R-group) - varies

Question 9

What are the identifying features of carbohydrates?

Answer 9

C(H20), linear or cyclic form, every carbon has a h20 attached to it

Question 10

What are the identifying features of nucleotides?

Answer 10

• Nitrogenous base (aromatic)
• Sugar
• Inorganic phosphate (mono, di or tri)

Question 11

What are the identifying feature of lipids?

Answer 11

Hydrocarbons, mainly contain hydrogen or carbon, may be aromatic or linear

Question 12

What is the defining feature of an unsaturated lipid?

Answer 12

contains carbon carbon double bounds (room for more H’s)

Question 13

What does residue refer to?

Answer 13

What’s left of a monomer in a polymer, water is lost,

Question 14

How are polymers attached (polymer)?

Answer 14

via covalent bounds

Question 15

Amino acids are linked by _____ to form _____ (___)

Answer 15

peptide bounds, polypeptides, proteins

Question 16

Nucleotides are linked by _____ to form _____ (___)

Answer 16

phosphodiester bonds, nucleic acids, (RNA, DNA)

Question 17

Monosaccarides are linked by _____ to form _____ (___)

Answer 17

glycosidic bonds, polysaccharides, (starch, glycogen, cellulose)

Question 18

What is a primary structure?

Answer 18

a biopolymer’s primary structure is the sequence of monomers linked by covalent bounds

Question 19

What are the secondary and tertiary structures?

Answer 19

Higher levels of structure of bipolymers depending entirely on non-covalent bounds between atoms

Question 20

What are hydrogen bonds?

Answer 20

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.

Question 21

What are salt bridges?

Answer 21

biological molecules contain numerous organic functional groups which are constitutively charged at physiologic pH and can thus make ionic interactions with one another

Question 22

How many hydrogen bounds are possible per water molecules?

Answer 22

4, 2 donors and 2 acceptors

Question 23

Water is highly….

Answer 23

cohesive

Question 24

What kind of structure does ice have?

Answer 24

a crystalline lattice structure

Question 25

Water molecules behave in a way that...? what does this result in?

Answer 25

maximizes their interaction with each other (maximum entropy) at any time resulting in the hydrophobic effect.

Question 26

What do proteins do (5)?

Answer 26

``` EVERYTHING!! Structure - connective tissue Movement - muscle Catalysis - enzymes (metabolism) Transport - Hb-O2, across cell membranes Communication - receptors and signalling ```

Question 27

What determines the function of a protein?

Answer 27

Its structure

Question 28

What are the two main classes of protein structure?

Answer 28

Globular or fibrous

Question 29

What is a globular protein?

Answer 29

proteins folded into a spherical (globular) shape. The can be enzymes, transporter proteins, receptors

Question 30

What is a fibrous protein?

Answer 30

Protein formed into filaments and are usually used to construct connective tissue, tendons, bone, matrix and muscle fiber

Question 31

What are the two major purposes of metabolism?

Answer 31

obtain usable chemical energy from the environment, make specific molecules that cells need to live and grow

Question 32

What are the two major types of metabolic pathways?

Answer 32

Catabolic, anabolic

Question 33

What are the catabolic pathways?

Answer 33

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

Question 34

What are the anabolic pathways?

Answer 34

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

Question 35

How many metabolic reaction occur in the human body?

Answer 35

over 500

Question 36

All metabolic pathways obey the same _______

Answer 36

fundamental principles

Question 37

Not all reactions occur in every ______ and not all reactions occur in every ______

Answer 37

organism, celll

Question 38

What is a metabolic pathway?

Answer 38

a series of consecutive, enzyme-catalyzed reactions producing a specific product from a specific starting metabolite

Question 39

How are the metabolic intermediates maintained at a steady level?

Answer 39

1. irreversible reactions (rate-limiting reactions) -- the enzymes that catalyze these are tightly regulated 2. Reversible reactions - direction depends on concentration of intermediates -- enzymes are not regulated

Question 40

What are the three major fuels for cellular catabolism? What are these broken down into?

Answer 40

proteins, carbs, lipids | Acetyl-CoA

Question 41

What does acetyl-CoA feed into?

Answer 41

the citric acid cycle, and is broken down to CO2

Question 42

Where are electrons from Acetyl-CoA

Answer 42

Electrons from the acetyl-CoA are "saved" in electron carriers (enzyme cofactors) - NADH and FADH2

Question 43

Where are the reduced electron carriers re-oxidized and what does this require? What is the energy of the electrons used to produce?

Answer 43

via the electron transport chain, oxygen (which is converted into water), ATP

Question 44

What maintains fuel molecules in the blood stream?

Answer 44

the liver

Question 45

What transports fuel molecules to the liver?

Answer 45

the hepatic portal vein

Question 46

How does the liver process fuel molecules (3)?

Answer 46

- Catabolism (immediate energy needs of hepatocytes) - Storage of excess fuel molecules - Processing/release into the blood stream for other organs/tissues

Question 47

How and where is glucose stored?

Answer 47

As glycogen in the liver and skeletal muscle

Question 48

How and where are fatty acids stored?

Answer 48

as fat (triacylglcerols) in adipocytes

Question 49

What are the two types of organ specialization in metabolism?

Answer 49

Fuel Users and Fuel providers

Question 50

What kind of fuel does the brain use?

Answer 50

Obligatory glucose user --> will switch to ketones if necessary

Question 51

The liver maintains ______ in the blood for the use of all other tissues

Answer 51

suitable levels of fuel molecules

Question 52

How does the liver maintain suitable levels of fuel molecules?

Answer 52

Using it's own glycogen stores --> glucose, Fatty acids from food or tissue --> ketone bodies, (sometimes amino acids --> glucose)

Question 53

What is the primary function of adipose tissue

Answer 53

long-term storage of energy