Bio-molecules "Cheat Sheet - MrsDScience

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Feb 20, 2013 (4 years and 4 months ago)

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Cheat Sheet

Molecular & Cell Biology For Dummies

From

Molecular and Cell Biology For Dummies

by Rene Fester Kratz, PhD

Studying molecular and cell biology can be challenging, but it's necessary if you want to pursue microbiology,
biotechnology, or genetics. Understanding molecular and cell biology entails kno
wing the four groups of macromolecules;
the processes of central dogma and cellular respiration; and essential components of eukaryotic cells.

Four Groups of Macromolecules

Macromolecules are just that
-

large molecules. The four groups of macromolecules,
shown in the table below, are
essential to the structure and function of a cell.

Group

Building Block

Large Molecule

Function

To Identify, Look for . . .

Carbohydrate

Monosaccharide

Polysaccharide

Energy storage,
receptors, structure
of plant cell wall

Made of C,H, and O;

OH's
on all carbons except one

Protein

Amino acid

Polypeptide or
protein

Enzymes,
structure,
receptors,
transport, and
more

Contain N, have N
-
C
-
C
backbone

Nucleic acid

Nucleotide

Polynucleotide or
nucleic acid

Information
storage and

transfer

Contain N in rings,
nucleotides made of sugar,
phosphate and nitrogenous
base

Lipid *

Glycerol, fatty
acids

Fats, oils, waxes,
phosopholipids,
steroids

Membrane
structure, energy
storage, insulation

Made of C,H, and O; lots of
C
-
H bonds; may
have some
C=C bonds (unsaturated);
steroids have 4 rings

*Lipids are not
polymers.





Central Dogma of Molecular Biology

In molecular and cell biology,

central dogma

is the passage of information from DNA to RNA to protein. Here's a brief
breakdown of
central dogma's process:

Process

What Is
Made?

What Is
Template?

Important Molecules

Starts At

Ends When

Replication

DNA

DNA

DNA polymerase, primase,
helicase, DNA ligase,
topoisomerase

Origin of
replication
(ORI)

Replication forks
meet

Transcription

RNA

DNA

RNA polymerase

Promoter

Termination
sequence

Translation

Polypeptide
(protein)

mRNA

Ribosome, tRNA

Start codon
(AUG)

Stop codon
(UAA, UGA,
UAG)

Important Parts of Eukaryotic Cells

All eukaryotic cells have organelles, a nucleus, and many internal
membranes. These components divide the eukaryotic
cell into sections, with each specializing in different functions. Each function is vital to the cell's life.



The

plasma membrane

is made of phospholipids and protein and serves as the selective boundary of

the cell.



The

nucleus

is surrounded by a nuclear envelope with nuclear pores. The nucleus stores and protects the DNA of the
cell.



The

endomembrane system

consists of the endoplasmic reticulum, the Golgi apparatus, and vesicles. It makes lipids,
membrane
proteins, and exported proteins and then “addresses” them and ships them where they need to go.



Mitochondria

are surrounded by two membranes and have their own DNA and ribosomes. They transfer energy from
food molecules to ATP.



Chloroplasts

are surrounded
by two membranes, contain thylakoids, and have their own DNA and protein. They
transform energy from the sun and CO2 from atmosphere into food molecules (sugars).



The

cytoskeleton

is a network of proteins: actin microfilaments, microtubules, and intermedia
te filaments. Cytoskeletal
proteins support the structure of the cell, help with cell division, and control cellular movements.

Cellular Respiration in Molecular Biology

Cellular respiration is your body's way of breaking down food molecules (carbohydrates
, proteins, and fats) and making
their stored energy available to the cell. Here's a brief overview:

Phase

Location in
Eukaryotic Cell?

Molecules That
Enter?

Molecules
Produced?

Links to Other Phases?

Glycolysis

Cytoplasm

Glucose, 2
NAD+, 2 ADP +
P

2
pyruvate, Net 2
ATP, 2 NADH +
H+

Pyruvate to linking step;
NADH to ETC

Linking step
(pyruvate
oxidation)

Matrix of
mitochondrion

2 pyruvate,
2NAD+

2 NADH + H+, 2
CO2, 2 acetyl
-
coA

NADH to ETC, acetyl
-
coA to Krebs

Krebs Cycle

Matrix of
mitochondrion

2 Ace
tyl
-
coA, 6
NAD+, 2 FAD

6 NADH + H+, 2
FADH2, 2 ATP, 4
CO2

NADH to ETC, FADH2
to ETC

Electron
Transport Chain
(ETC)

Inner membrane of
mitochondrion

NADH, FADH2,
ADP + P

3 ATP per NADH,
2 ATP per FADH2

NAD+ to glycolysis,
linking step & Krebs,
FAD to Krebs