CH250: Chapter 1 - Principles of Biochemistry

What did Eduard Buchner Discover?

fermentation

via a cell-free extract of yeast cells ("press juice"), which could still ferment sugars

In Buchner's experiment, why was the "press juice" able to ferment sugars?

b/c the dead yeast left their enzymes behind

(T/F) Pasteur was able to replicate Buchner's cell-free fermentation

FALSE

Why was Buchner successful when others, like Pasteur, were unable to replicate his experiment?

b/c Buchner used ...

> quartz sand + diatomaceous earth to grind his yeast

> 40% sucrose as a preservative

> used a better strain of yeast than Pasteur

Name the Hierarchy of Life from least to most complex.

elements/ functional groups, biomolecules, macromolecules, metabolism, cells, organisms, Ecosystems

What group is at the bottom of the Hierarchy of Life?

elements/ functional groups

What group is at the top of the Hierarchy of Life?

Ecosystems

(T/F) Organisms are at the top of the Hierarchy of Life

FALSE

ecosystems are at the top

What's the molecular geometry of a carbon atom with 4 bonds?

tetrahedral

(T/F) You can easily rotate around a carbon-carbon pi-bond

FALSE

you cannot rotate around a C=C pi-bond w/o breaking it

Silicon and carbon share many properties, but there are problems with silicon-based life. What are they?

> it can only form bonds with a few types of elements

>it has difficult forming double/ triple bonds (b/c silicon is bigger than carbon)

>SiO2 is a non-soluble solid

What do trace elements do?

they're used as cofactors in proteins

(T/F) Trace elements are used a cofactors in proteins

TRUE

(T/F) Trace elements are important, but not required for life

FALSE

trace elements are required for life

(T/F) Trace elements are required in same amounts as elements

FALSE

trace elements are required in TRACE amounts compared to elements

Examples of Trace Elements

zinc, iron, manganese, copper, cobalt

(T/F) Magnesium is a Trace element

FALSE

magnesium is an essential ion, manganese is a trace element

(T/F) Manganese is a Trace element

TRUE

(T/F) Essential ions are used as cofactors in proteins

FALSE

trace elements are used as cofactors in proteins

What do essential ions do?

play a key role in cell signalling AND neurophysiology

(T/F) Essential ions play a key role in cell signalling and neurophysiology

TRUE

Examples of Essential Ions

calcium, potassium, magnesium, sodium, chloride

(T/F) Functional groups play an important role in structure and function of biomolecules

TRUE

(T/F) Functional groups mainly play an important role in the function of biomolecules

FALSE

they play an important role in both the structure AND function of biomolecules

What are the 4 major Classes of Small Biomolecules?

amino acids, nucleotides, simple sugars, fatty acids

Primary functions of amino acids?

protein function

neurotransmission

nitrogen metabolism

energy conversion

Primary functions of nucleotides?

nucleic acid function

enzyme catalysis

signal transduction

energy conversion

Primary functions of simple sugars?

cell recognition

cell wall structure

nucleotide structure

energy conversion

Primary functions of fatty acids?

cell membranes

cell signalling

energy storage

energy conversion

What are proteins the polymers of?

amino acids

What are nucleic acids the polymers of?

nucleotides

What are polysaccharides the polymers of?

monosaccharides (like glucose, fructose, galactose)

When there's high energy in the cell, enzymes will catalyze the (synthesis/ degradation) of polymers

synthesis

When there's low energy in the cell, enzymes will catalyze the (synthesis/ degradation) of polymers

degradation

What links nucleotides?

3',5'-phosphodiester bonds (covalent)

(T/F) a DNA octamer can have 4^8 different sequence combinations

TRUE

b/c each of the 8 positions can have one of 4 nucleotides

What links amino acids?

peptide bonds (covalent)

What links monosaccharides (simple sugars) ?

glycosidic bonds

Types of Glycosidic Bonds

alpha (1->4)

beta (1->4)

beta(1->4) **where simple sugars have nitrogen

Anomeric carbon

formed when the carbonyl carbon of an OPEN chain becomes a carbon single bonded to 2 oxygens in a CLOSED ring

Metabolites

biomolecules that serve as reactants AND products during biochemical RXNs

Metabolic flux

rate that reactants and products are interconverted in a metabolic pathway

(T/F) Base composition changes with age, nutritional state or environmental changes

FALSE

(T/F) Base composition varies between species

TRUE

Chargaff's Ratios

A=T and G=C

A+G = T+C

Deoxyribonucleotides

monomers of DNA

lack an -OH group on 2' carbon of ribose sugar

Ribonucleotides

monomers of RNA

have -OH group on 2' (and 3') carbon of ribose sugar

In nucleotides, on what carbons are the OH groups?

2' and 3' carbons in RNA

only 3' carbon in DNA

In nucleotides, on what carbon is the phosphoryl group on?

5' carbon

In nucleotides, on what carbon is the nucleotide base on?

1' carbon

What bonds hold base pairs together? How many do each pair have?

hydrogen bonds

A-T, 2 H-bonds

G-C, 3 H-bonds

(T/F) Mutations in germ-line cells can result in inherited genetic diseases

TRUE

(T/F) Mutations in somatic cells do not result in inherited genetic diseases

TRUE

(T/F) Mutations in somatic cells are limited to individual organisms, and can result in cancer

TRUE

Homologous Genes (homologs)

shared common ancestor

genes are either homologous OR not (cannot have percent homology)

(T/F) Homologs include orthologs and paralogs

TRUE

Orthologous Genes (orthologs)

homologs from DIFFERENT species

a result of speciation

gene/ main functions are conserved

Paralogous Genes (paralogs)

homologs WITHIN a species

a result of a gene duplication event within the species

3 Outcomes of a Gene Duplication Event

(1) BOTH genes are kept

(2) ONE of the two genes mutates, acquiring a new function

(3) ONLY ONE gene is kept, the other is discarded

(T/F) Orthologs and Paralogs are types of homologs

TRUE

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