Biology
News log
- Evolution = atheism, no purpose. ‘Let me summarize my views on what modern evolutionary biology tells us loud and clear … There are no gods, no purposes, no goal-directed forces of any kind. There is no life after death. When I die, I am absolutely certain that I am going to be dead. That’s the end for me. There is no ultimate foundation for ethics, no ultimate meaning to life, and no free will for humans, either.’
- Janine
Benyus: Biomimicry in action. Posted August, 2009. Amazing examples
of design in nature. Here she reveals dozens of new products that
take their cue from nature with spectacular results. Also see: AskNature.org.
Creationism and Arguments for Design (some are YouTube videos)
The debate over origins is between the concepts of (intelligent)
"design" versus (laws of) chance and (laws of) nature. In
other words, can the origin of life be best explained from chance
and inherent laws of nature or does it require an outside source of
intelligence (i.e. information, knowledge, design, etc). That is,
can the complexity of life (design) best be explained with or without
a designer.
The properties of information are: (1) not bound to its medium, (2)
massless, (3) intangible, (4) immaterial (e.g. technologies, works
of art, biological systems), and (5) abstract construct of mind. "There
is no known natural law through which matter can give rise to information,
neither is any physical process or mateiral phenomenon known that
can do this."
More than just matter + energy. There is also "information".
- What
are the most abundant proteins in a cell?
- Discoveries
Make the "Junk DNA" Rubble Bounce. Published 1/24/2013.
In a process called alternative splicing, a single gene could code
for multiple proteins with different biological functions. In this
way, alternative splicing allows the human genome to direct the synthesis
of many more proteins than would be expected from its 20,000 protein-coding
genes.
- Human
genome at ten: Life is complicated. The more biologists look,
the more complexity there seems to be. Few predicted, for example,
that sequencing the genome would undermine the primacy of genes by
unveiling whole new classes of elements....We fooled ourselves into
thinking the genome was going to be a transparent blueprint, but it's
not. Instead, as sequencing and other new technologies spew forth
data, the complexity of biology has seemed to grow by orders of magnitude.
Delving into it has been like zooming into a Mandelbrot set
a space that is determined by a simple equation, but that reveals
ever more intricate patterns as one peers closer at its boundary....It
seems like we're climbing a mountain that keeps getting higher and
higher. The more we know, the more we realize there is to know....Much
non-coding DNA has a regulatory role; small RNAs of different varieties
seem to control gene expression at the level of both DNA and RNA transcripts
in ways that are still only beginning to become clear. "Just
the sheer existence of these exotic regulators suggests that our understanding
about the most basic things such as how a cell turns on and
off is incredibly naive.
- Stephen
Meyer - Genetics Proves Design and Disproves Evolution PT 1 of 2.
- Stephen
Meyer - Genetics Proves Design and Disproves Evolution PT 2 of 2.
- 250
million yr old bacteria revived? Throw him under the bus! Reference
this article: Alive...after
250 million years. Ancient bacteria trapped in a state of suspended
animation for 250 million years are the world's oldest living things,
claim US scientists. The microbes are ten times older than any previously
discovered living organism...The bacteria were found in salt crystals
buried almost 609 metres (2,000 feet) below ground at a cavern in
south-east New Mexico, US.
- How
DNA Killed Evolutionism pt 1 of 4.
- The
Miller-Urey experiment. Refutation of the experiment which produced
a handful of amino acids. Headings: (1) Irrelevant atmosphere - required
absence of oxygen and nitrogen, and inclusion of unstable compounds
(ammonia decomposes within 30,000 years; methane decomposes in 1%
of the earth's lifetime; hydrogen does not exist in element form on
this planet). (2) Irrelevant conditions - required a circulatory system,
cooling system to isolate and protect from further reactions, and
directed energy source. (3) Low yield - tiny quantities. As the amino
acids were formed they reacted with reducing sugars, forming a brown
tar around Miller's apparatus. (4) Wrong forms of amino acid - left
versus right-handed amino acids. It is not a simple process to separate
them and there is no natural system that can do so. In fact, L-amino
acids have a tendency with age to undergo a chemical inversion to
the D-form. This is called racemization.
Miller-Urey experiment
The
Miller-Urey experiment. Refutation of the experiment which produced
a handful of amino acids. Headings:
- Irrelevant atmosphere - required absence of oxygen and nitrogen,
and inclusion of unstable compounds (ammonia decomposes within 30,000
years; methane decomposes in 1% of the earth's lifetime; hydrogen
does not exist in element form on this planet).
- Irrelevant conditions - required a circulatory system, cooling
system to isolate and protect from further reactions, and directed
energy source.
- Low yield - tiny quantities. As the amino acids were formed
they reacted with reducing sugars, forming a brown tar around Miller's
apparatus. That is, the destruction of the key compounds by the prevailing
conditions or by other chemical by-products.
- Wrong forms of amino acid - left versus right-handed amino
acids. It is not a simple process to separate them and there is no
natural system that can do so. In fact, L-amino acids have a tendency
with age to undergo a chemical inversion to the D-form. This is called
racemization.
- The problem of building a protein - We now need the amino
acids to join together (polymerise) to form proteins. It requires
the removal of water molecules. This does not occur naturally. Proteins
range in chains of 25 to 50,000 amino acids. What are the odds of
producing just one average protein of 150 amino acids by chance? The
math: 20 to the 150th power. However, a living cells contains thousans
of proteins. A simple bacteria has over 4,000. Humans have over 2
million and counting. BUT, assume a protein was formed, the next problem
is the correct "folding" of the protein. Incorrect folding
makes it biologically inactive.
- Other chemicals needed for life - Carbohydrates, lipids,
and nucleic acids.
- No DNA/RNA formation - There has been no experimental indication
of the formation of either RNA or DNA in a Miller-type synthesis.
The problem of the origin(s) of life remains. All that has been
outlined is speculation and, despite tremendous advances in biochemistry,
answers to the problem remain hypothetical.
Details of the
transition from complex non-living materials to simple living organisms
remain a mystery.
Cell Biology (all are YouTube videos)
RNA Polymerase
- RNA
Polymerase. First RNA: RNA is a versatile molecule. In its most
familiar role, RNA acts as an intermediary, carrying genetic information
from the DNA to the machinery of protein synthesis. RNA also plays
more active roles, performing many of the catalytic and recognition
functions normally reserved for proteins. In fact, most of the RNA
in cells is found in ribosomes--our protein-synthesizing machines--and
the transfer RNA molecules used to add each new amino acid to growing
proteins. In addition, countless small RNA molecules are involved
in regulating, processing and disposing of the constant traffic of
messenger RNA.
The enzyme RNA polymerase carries the weighty responsibility of creating
all of the different RNA molecules the cell uses. RNA polymerase is
a huge factory with many moving parts. It is composed of a dozen different
proteins. Together, they form a machine that surrounds DNA strands,
unwinds them, and builds an RNA strand based on the information held
inside the DNA. Once the enzyme gets started, RNA polymerase marches
confidently along the DNA copying RNA strands thousands of nucleotides
long.
DNA and Protein Synthesis -- by Craig Savage (all are YouTube
videos)
Enzymes in DNA/RNA synthesis (YouTube videos)
- Helicase. In humans, 95 non-redundant helicases are coded
for in the genome, 64 RNA helicases and 31 DNA helicases.[2] Many
cellular processes, such as DNA replication, transcription, translation,
recombination, DNA repair, and ribosome biogenesis involve the separation
of nucleic acid strands that necessitates the use of helicases.
- Primase. Primase is of key importance in DNA replication
because no known DNA polymerases can initiate the synthesis of a DNA
strand without an initial RNA or DNA primer (for temporary DNA elongation).
- Topoisomerase. Topoisomerases are enzymes that regulate the
overwinding or underwinding of DNA. The winding problem of DNA arises
due to the intertwined nature of its double helical structure. For
example, during DNA replication, DNA becomes overwound ahead of a
replication fork. If left unabated, this tension would eventually
grind replication to a halt (a similar event happens during transcription.)
(YouTube)
Topoisomerase 1 and 2.
- Polymerase. A polymerase is an enzyme whose central biological
function is the synthesis of polymers of nucleic acids. DNA polymerase
and RNA polymerase are used to assemble DNA and RNA molecules, respectively,
generally by copying a DNA or RNA template strand using base-pairing
interactions.
- Ribosome. The ribosome (from ribonucleic acid and the Greek
soma, meaning "body") is a large and complex molecular machine,
found within all living cells, that serves as the primary site of
biological protein synthesis (translation). Ribosomes link amino acids
together in the order specified by messenger RNA (mRNA) molecules.
Ribosomes consist of two major subunitsthe small ribosomal subunit
reads the mRNA, while the large subunit joins amino acids to form
a polypeptide chain. Each subunit is composed of one or more ribosomal
RNA (rRNA) molecules and a variety of proteins.
- Transfer Molecules.
DNA to Protein (YouTube videos)
It is estimated that the human body may contain over two million
proteins, coded for by only 20,000 - 25,000 genes. The total number
of proteins found in terran biological organisms is likely to exceed
ten million, but nobody knows for sure. Data is available on just
over a million proteins, taken mainly from information found in the
~100 genomes which have been fully sequenced as of 2007....The longest
known protein, titin, also known as connectin, contains 26,926 amino
acids. Titin is found in muscle and contributes to its passive stiffness.
The word protein comes from the Greek prota, meaning "of primary
importance". This is a suitable name, as the central importance
of proteins in the human body can not be overestimated. All biological
organisms can be seen fundamentally as protein structures filled with
water and sometimes supported by mineralized tissues called bone.
For almost every protein there is another protein that can break it
down. Proteins sometimes coalesce into mutually cooperative units
called complexes, which perform useful biological functions. Every
section of useful genetic information, found in DNA and some RNA,
codes for a corresponding protein which goes on to fulfill a useful
biological role.
Chromosomes
The human (Homo sapiens) genome is the complete set of human genetic
information, stored as DNA sequences within the 23 chromosome pairs
of the cell nucleus, and in a small DNA molecule within the mitochondrion.
The haploid human genome (contained in egg and sperm cells) consists
of three billion DNA base pairs, while the diploid genome (found in
somatic cells) has twice the DNA content.
The haploid human genome contains approximately 20,000 protein-coding
genes, significantly fewer than had been anticipated. Protein-coding
sequences account for only a very small fraction of the genome (approximately
1.5%), and the rest is associated with non-coding RNA molecules, regulatory
DNA sequences, introns, and sequences to which no function has yet
been assigned.
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