Biodiversity: animals moving around and adapting
Allele: Genetic trait
Genetic drift: a change in the frequency of an allele within a population over time
The complexities of evolution
The study of how animals adapt, find a niche, and survive.
What is a virus?
A virus reproduces inside the cells of living hosts, a host cell is forced to produce thousands of identical copies of the original virus.
Viruses consist of nucleic acid and a protein coat.
Usually the nucleic acid is RNA; sometimes it is DNA. ...
Viruses are much smaller than bacteria.
They lack the means for self-reproduction outside a host cell and are therefore generally not considered to be true living organisms.
Without a host cell, viruses cannot carry out their life-sustaining functions or reproduce.
They cannot synthesize proteins, because they lack ribosomes and must use the ribosomes of their host cells to translate viral messenger RNA into viral proteins.
Viruses cannot generate or store energy in the form of adenosine triphosphate (ATP), but have to derive their energy, and all other metabolic functions, from the host cell. They also parasitize the cell for basic building materials, such as amino acids, nucleotides, and lipids (fats).
All viruses contain nucleic acid, either DNA or RNA (but not both), and a protein coat, which encases the nucleic acid. Some viruses are also enclosed by an envelope of fat and protein molecules.
The Place where nerve communication Ends and begins
A junction between two nerve cells, a gap across which impulses pass by diffusion of a neurotransmitter.
An organic chemical that functions in the brain and body of many types of animals as a neurotransmitter—a chemical message released by nerve cells to send signals to other cells, such as neurons, muscle cells and gland cells.
What do ribosomes make?
1. What is transcription?
2. Where does it take place?
3. What is translation?
4. Where does it take place?
5. What is a codon? Where is it?
6. How does DNA three letter code get converted into an amino acid?
Types of Proteins
a red protein responsible for transporting oxygen in the blood of vertebrates. It contains an iron atom bound to a heme group.
Insoluble, usually high-sulfur content and filament-forming proteins.
The bulk of epidermal appendages such as:
hair, nails, claws, turtle scutes, horns, whale baleen, beaks, and feathers.
These keratinous materials are formed by cells filled with keratin and are considered ‘dead tissues’.
Keratin structures are among the toughest biological materials, serving as a wide variety of interesting functions, e.g. scales to armor body, horns to combat aggressors, hagfish slime as defense against predators, nails and claws to increase prehension, hair and fur to protect against the environment
Keratin is in skin.
Keratin production related illness
Mutations in the ABCA12 gene cause harlequin ichthyosis.
The ABCA12 gene provides instructions for making a protein that is essential for the normal development of skin cells.
This protein plays a major role in the transport of fats (lipids) in the outermost layer of skin (the epidermis).
This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations.
The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.
A mixture of proteins and phospholipids forming a whitish insulating sheath around many nerve fibers, increasing the speed at which impulses are conducted.
Nerve Cells COnnect to Muscles
Also called neurilemma cell, any of the cells in the peripheral nervous system that produce the myelin sheath around neuronal axons. Schwann cells are named after German physiologist Theodor Schwann, who discovered them in the 19th century.
We are made of many elements
Protein Structure as a result of Folding
DNA Nucleotide Bonding
What is DNA?
So far we have said that DNA:
is a double helix
Has a sugar phosphate backbone
contains instructions to make proteins
coils into a chromosome
is in the nucleus of a cell
has nucleotide pairs
We will now learn more about what this means
The following are some of the components, they will help us learn prefixes, how to dissect words:
a pentose is a monosaccharide (simple sugar) with five carbon atoms.
a sugar derived from ribose by replacing a hydroxyl group with hydrogen.
de- (expressing reduction) + oxy-2 + ribose.
RNA has ribose, DNA has deoxyribose
DNA RNA comparison
Triphosphate, diphosphate, monophosphate:
phosphate- phosphorous groups
Nitrogenous base: a nitrogen-containing molecule that has the same chemical properties as a base.
They are particularly important since they make up the building blocks of DNA and RNA: adenine, guanine, cytosine, thymine and uracil.
Purines and Pyrimidines
Bases found in DNA are ATCG
Bases found in RNA are AUCG
RNA is usually single stranded,
DNA is usually double stranded
mRNA is a small "photocopy" of genetic information
DNA is the cell's archive for genetic information passed down from one generation to the next generation
A gene is a part or segment of DNA
any of the series of saturated hydrocarbons including methane, ethane, propane, and higher members.
Nomenclature of alkanes
In chemistry, a phosphate is an anion, salt, functional group or ester derived from a phosphoric acid.
Carbonyl Group (aldehyde and ketones):
a functional group composed of a carbon atom double-bonded to an oxygen atom: C=O
An abbreviation for any group in which a carbon or hydrogen atom is attached to the rest of the molecule.
Carboxylic Acid Group:
an organic compound that contains a carboxyl group (C(=O)OH). The general formula of a carboxylic acid is R–COOH, with R referring to the alkyl group.
Carboxylic acids occur widely. Important examples include the amino acids and acetic acid.
Groups are polar, and the oxygen side is always negative, while the hydrogen side is always positive.
An amide is a functional group containing a carbonyl group linked to a nitrogen atom or any compound containing the amide functional group.
Amino Acid Structures
The water molecule is made up of oxygen and hydrogen, with respective electronegativities of 3.44 and 2.20.
The electronegativity difference polarizes each H–O bond, shifting its electrons towards the oxygen (illustrated by red arrows).
These effects add as vectors to make the overall molecule polar.
Sulfhydryl group (thiol)
Esther and Ether
Bonds in DNA
Acids and Bases
Acids donate H ions, bases take them
Connect Genetics to Protein Synthesis
WHat is a gene?
DNA Transcription and Translation
RNA is synthesized from DNA by an enzyme known as RNA polymerase during a process called transcription.
The new RNA sequences are complementary to their DNA template, rather than being identical copies of the template.
RNA is then translated into proteins by structures called ribosomes.
Messenger RNA (mRNA) carries the instructions to make a particular protein of the DNA from the nucleous to the ribosomes.
The process of producing mRNA from instructions in the DNA is called transcription.
During transcription, the DNA molecule unwinds and separates exposing the nitrogenous bases.
Free RNA nucleotides pair with the exposed bases.
No thymine (T) is in RNA. Uracil (U) pairs with adenine (A) instead.
RNA contains the sugar ribase instead of deoxyribose.
The mRNA molecule is completed by the formation of bonds between the RNA nucleotides, and it then separates them from the DNA.
The mRNA molecule is a single strand, unlike DNA.
Chitin is a protein in mushrooms, also sea sponges, crustaceans, and insects
They have chitinous teeth:
Fish with cartilage skeletons
There is a chitin/fish connection here:
Chitin based barrier in some fish:
Chitin Molecular Structure
Structure and FUnction
The Punnett square is a square diagram that is used to predict the genotypes of a particular cross or breeding experiment.
It is named after Reginald C. Punnett.
The diagram is used by biologists to determine the probability of an offspring having a particular genotype.
A monohybrid cross is a breeding experiment between P generation (parental generation) organisms that differ in a single given trait. The P generation organisms are homozygous for the given trait.
Dihybrid cross is a cross between two different lines/genes that differ in two observed traits. According to Mendel's statement, between the alleles of both these loci there is a relationship of completely dominant - recessive traits.
Examples of Dominant vs Recessive Genes
An allele that produces the same phenotype whether its paired allele is identical or different
An allele that produces its characteristic phenotype only when its paired allele is identical
Sequence of a gene's DNA that transcribes into protein structures
Physical genetic expression
Internal genetic expression
Variation of a genetic trait
a Sex cell
Conversion of the information encoded in a gene first into messenger RNA and then to a protein
Calico cats are almost always female because the locus of the gene for the orange/non-orange coloring is on the X chromosome.
Sickle cell: In sickle cell anemia, blood is also chronically low in oxygen
Olympic Medalist Sarah Winckless:
The endosymbiosis theory proposes that cyanobacteria may have evolved into the chloroplasts that exist in plant cells today (Gault and Marler, 2009)
Cyanobacteria don't have chloroplasts. Instead, the chlorophyll is stored in thylakoids in their cytoplasm.
Diazotrophs are able to conduct nitrogen fixation.
Cyanobacteria can convert inert, atmospheric nitrogen into an organic form (e.g. nitrate or ammonia) that other organisms, including plants, can use.
'True plants' are not able to do this. They can only use the organic form of nitrogen and have to rely man-made fertilisers or form a symbiotic relationship with diazotrophs (nitrogen-fixing bacteria).
The nitrogen cycle:
Nitrogen is cycled through an ecosystem by both plants and animals.
Decomposers break down dead organisms and their waste products to release ammonia in a process called ammonification.
Organisms called nitrifying bacteria convert this ammonia into nitrates in a process called nitrification.
These nitrates can be used by plants to make amino acids.
The process of converting nitrogen in the atmosphere to ammonia is called nitrogen fixation.
This process is carried out by bacteria that live in the soil and in plant roots.
Plants can absorb both ammonia and nitrates from the soil, but animals cannot.
Animals obtain nitrogen by eating plants and other organisms and then digesting the proteins they contain.
Nitrogen is needed for proteins and for DNA structures
Proteins are chains of amino acids, polymers, long chains of repeating units:
Nitrogen forms peptide bonds:
a compound consisting of two or more amino acids linked in a chain, the carboxyl group of each acid being joined to the amino group of the next by a bond of the type -OC-NH-.
And these peptide bonds form chain of amino acids:
Nucleic Bases are in DNA and RNA:
DNA is organized into a double helix:
DNA is bundled up into chromosomes:
RNA is half of the DNA strand:
RNA has Uracil instead of Thymine
RNA is read by ribosomes in DNA Translation to make proteins by linking amino acids to make chains of amino acids, polymers, also called polypeptides.
Genetic sequences in chromosomes are called genes
plural noun: genes
(in informal use) a unit of heredity which is transferred from a parent to offspring and is held to determine some characteristic of the offspring.
"proteins coded directly by genes"
(in technical use) a distinct sequence of nucleotides forming part of a chromosome, the order of which determines the order of monomers in a polypeptide or nucleic acid molecule which a cell (or virus) may synthesize.
Chromosomes go through changes to create a variety of gametes
Crossing over occurs between prophase I and metaphase I of meiosis, some genes are swapped to create unique gametes.
A gamete is a mature haploid male or female germ cell which is able to unite with another of the opposite sex in sexual reproduction to form a zygote.
Gamete production is meiosis:
Life forms have gone from tiny archaea, to single celled prokaryotes, to complex multi-cellular organisms that have tissues that form organs.
Speciation is the forming of a whole new species.
Adaptation comes from changes in genetics that help the species survive.
New species may result from adaptation and niche filling.
To reduce competition creatures might engage in different behaviors, or eat different, things and eventually become a different species.
Animals that are able to survive are able to pass on their genes and their offspring are better able to survive.
Genes can affect color, shape, behavior, scent, and texture.
In evolutionary biology, adaptive radiation is the process of quick adaptation and change as members of a species find different niches and become separate species, this may happen when a change in the environment makes new resources available, creates new challenges, or opens new environmental niches.
Author: Jazmin Gannon
A place to grow