Sunday, August 25, 2013

Describing each of the four Organic Compounds which are the basis for life

Carbohydrates: Made from joining H2O and COby plants during photosynthesis


Monomer: Simple sugars: CH2O (ratio of one carbon and one oxygen to every 2 hydrogens)Bread, cereal, potatoes, fruits, vegetables, and pasta = are made mostly of carbohydrates (sugars and starches).

Functions: energy for cells, structural support, cell-cell communication


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Lipids: are different molecules that are insoluble in water, fats, made of alcohol and fatty acids.

Monomer: Glycerol and fatty acids

Functions: used to store energy


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Proteins: are the structural components of tissue and cells, made up of amino acids.

Monomer: Amino Acids

Functions: control the rate of reactions and regulate cell processes.


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Nucleic Acids: polymers,in DNA and RNA.

Monomer: Nucleotides

Functions: store and transmit hereditary of genetic information


Darwins Theory vs. Lamarck's ideas & Explaining Natural Selection & Evidence for evolution

LAMARCK proposed that individuals lose characteristics that they do not use, and develop further on characteristics that they use a lot. And that these changes would be inherited.

  • Ex. Giraffes stretching for branches generation after generation would lead to them having longer necks.


DARWIN'S theory of evolution was that all varieties of life descended from shared (in common) ancestors. This means complex creatures naturally evolved from simpler ancestors, over time. In other words more agile or better fit organisms tend to survive and to pass on their superior characteristics to subsequent generations.


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Natural Selection is the process whereby organisms better adapted to their environment tend to survive and produce more offspring. The theory of its action was first fully expounded by Charles Darwin and is now believed to be the main process that brings about evolution. 

Examples:

1. In a habitat there are green bugs and brown bugs. The birds prefer the taste of the green bugs, so soon there are many brown bugs and few green bugs. The brown bugs reproduce and make more brown bugs and eventually there are no more green bugs.


2. A species of rats live in a certain type of tree with the branches evenly spaced. Smaller rats could not reach from branch to branch and larger rats would break the branches and fall. Soon, all rats were just the right size for the tree branches. 


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During and since Darwin's time, people have been looking for and studying evidence in nature that teaches them more about evolution. Some types of evidence such as fossils and similarities between related living organisms, were used by Darwin to develop his theory of natural selection, and are still used today. Others, such as DNA testing, were not available in Darwin's time, but are used by scientists today to learn more about evolution. 

Evidence examples?
  • Ancient Organism remains
  • Fossil layers
  • Similarities among organisms alive today
  • Similarities in DNA
  • Similarities of Embryos 

Human Body Systems

Integumentary System



Purpose; To regulate the body's temperature and keep it at equilibrium and to protect the body.
Structure; The epidermis is the outter layer of skin and the dermis in the inner layer. Within these two layers there is the melanin which is the skin pigment, the kertain which is dead waterproofing cells and hair.
Organs needed; Dermis, Melanin, Keratin, Hair

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Muscular


Purpose; 
*Smooth muscles allow for contraction of organs and blood vessels. 
*Cardiac muscle pumps the heart.
*Skeletal muscle allows for movement.
Structure; 
*Smooth muscles are found in internal organs and blood vessels.
*Cardiac muscles is found in the heart.
*Skeletal muscles is attached to bones.
Organs needed; Smooth, Cardiac, and Skeletal muscle

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Skeletal


Purpose; Frame for the body's tissues protects the organs and produces blood cells.
Structure; Two parts: 
1. Axial Skeleton: is made up of the skull, the vertebral column, the ribs and the sternum.
2. Appendicular Skeleton: is made up of the bones in the arms and legs. 
Joints and ligaments hold bone to bone. Tendons connect muscle to bone
Organs needed; Skull, Bones, Vertebrae column, the Sternum, Joints, Ligaments, and Tendons

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Circulatory

Moving gif image of a typical human heart beating

Purpose; Move blood throughout the entire human body.
Structure; The veins carry the blood into the heart. Once to the heart the arteries carry the blood away from the heart and the rest of the body.
Organs needed; Heart, Arteries, Veins, and Cappillaries

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Digestive


Purpose; Digest food and gets the important nutrients out of the food.
Structure; Begins with the mouth then goes through the esophagus and to the stomach, small intestine, lager intestine, and ends in the rectum. The liver produces bile. The gall bladder stores the bile. The pancreas secrets digestive enzymes and hormones.
Organs needed; Mouth, Esophagus, Stomach, Small Intestine, Large Intestine, Rectum, Gall Bladder, Liver, and the Pancreas.

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Nervous


Purpose; Controls all function of the body. Breathing, Moving, Thinking etc.
Structure; The nerves carry messages from the brain to and from everywhere on the human body.
Organs needed; Brain, Nerves, and Spinal Cord

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Endocrine


Purpose; Regulates digestion, metabolism, and homeostasis.
Structure; These glands all produce hormones that instruct the body to do different thins in different situations.
Organs needed; Pituitary gland, Thyroid gland, Thymus gland, Pancreas, Tests, Ovaries, Adrenal, and Paratyroid gland.

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Reproductive


Purpose; To reproduce
Structure; 
Male- the testis produce sperm and the vas deferens as well as the urethra transport sperm.
Females- the ovary produces the egg and the uterus holds a baby.
Organs needed; 
Male- Testes, Vas Deferens, Urethra, and Penis
Female- Ovary, Uterus, Vagina

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Respiratory


Purpose; To provide the human body/blood with oxygen.
Structure; Air goes through the trachea and into the bronchi which then lead to the lungs which then branch into bronchioles that then lead to tiny air sacs called aveoli.
Organs needed; Bronchi, Lungs, Bronchioles, and Alveoli.

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Excretory (including the urinary)


Purpose; To filter and then remove wastes from the body.
Structure; The Kidney filters the blood then goes through the ureter to get to the urinary bladder wherethe urine is stored and then it makes it's way through the urethra and out the body.
Organs needed; Kidneys, Ureter, Urinary Bladder, and the Urethra

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Immune/Lymphatic



Purpose; To fight infections.
Structure; The lymph nodes and lymph vessels try to fight off anitgenes throughout the body.
Organs needed; Lymph nodes, Lymph vessels, tonsils, Thymus gland, Spleen, and Bone marrow. 


Saturday, August 24, 2013

Compare and Contrast Genotype & Phenotype

The Genotype is the genetic constitution of a cell, an organism, or an individual. For instance, the human albino gene has two allelic forms, dominant A and recessive a, and there are three possible genotypes- AA (homozygous dominant), Aa (heterozygous), and aa (homozygous recessive).

A Phenotype is any observable characteristic or trait of an organism; such as its morphology, development biochemical or physiological properties, or behavior. Phenotypes result from the expression of an organism's genes as well as the influence of environment factors and possible interactions between the two.


So Genotype is in the DNA and changes in the DNA. Phenotype is how the change looks like from outside. So what ever the result is from Genotype is seen by Phenotype. The mutation in the DNA or change in the Genotype necessarily doesn't show... while Phenotype is observable. 




Wednesday, August 21, 2013

Describe the process of Transcription & Translation in Eukaryotic Cells

During the process of transcription, transcription factors attach first to certain spots in the DNA. In eukaryotes, this spot usually the TATA box, segment of DNA with the code TATA. Then RNA polymerase comes down, pries apart the two DNA strands and binds as well. The complex formed by the DNA and the transcription factors are called the transcription initiation complex. Once the DNA has been transcribed, the resultant mRNA strand is called the primary transcript. Since eukaryotes have a nucleus, transcription is seperated from translation both temporally and spatially. Post-transcriptional modifications also must occur to protect the transcript from hydrolytic enzymes and help facilitate transport. A 5' cap is added to the 5' end and a long poly-A tail (long sequence of adenine bases) also added to the 3' end. Finally, introns are removed by a spliceosome complex. Introns are long uncoding sequences found between sequence that actually are translated into protein (exons). Two splieceosomes come in on either end of each intron and remove them. Then the mRNA exits the nucleus to be translated in the cyotosol.




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Translation, this is where the proteins are made using the codes of amino acids, the codes for these amino acids are found in the nucleus and needs to be translated into the ribosomes where proteins is made. A messenger called RNA is able to carry this information and transfers it to the ribosome. The RNA molecule then 'sticks' to the ribosome which then allows for all the amino acids which connect with the certain combinations of nucleotides to make proteings- which is just a chain of amino acids. RNA is simply one strand of the DNA which holds combinations of nucleotides. 

Compare and contrast Mitosis and Meiosis

MeiosisMitosis
Definition:A type of cellular reproduction in which the number of chromosomes are reduced by half through the separation of homologous chromosomes, producing two haploid cells.A process of asexual reproduction in which the cell divides in two producing a replica, with an equal number of chromosomes in each resulting diploid cell.
Function:sexual reproductionCellular Reproduction & general growth and repair of the body
Type of Reproduction:SexualAsexual
Occurs in:Humans, animals, plants, fungiall organisms
Genetically:differentidentical
Crossing Over:Yes, mixing of chromosomes can occur.No, crossing over cannot occur.
Pairing of Homologues:YesNo
Number of Divisions:21
Number of Daughter Cells produced:4 haploid cells2 diploid cells
Chromosome Number:Reduced by halfRemains the same
Steps:The steps of meiosis are Interphase, Prophase I, Metaphase I, Anaphase I, Telophase I, Prophase II, Metaphase II, Anaphase II and Telophase II.The steps of mitosis are Interphase, Prophase, Metaphase, Anaphase, Telophase and Cytokinesis
Karyokenesis:Occurs in Interphase IOccurs in Interphase
Cytokenesis:Occurs in Telophase I & Telohpase IIOccurs in Telophase
Centromeres Split:The centromeres do not separate during anaphase I, but during anaphase IIThe centromeres split during Anaphase
Creates:Sex cells only: Female egg cells or Male sperm cellsMakes everything other than sex cells
Discovered by:Oscar HertwigWalther Flemming

Compare and contrast Mitosis & Binary Fission

Mitosis- is the division of the nucleus in a diploid cell (that is a cell containing 2 sets of chromosomes). It occurs in Eukaryotic cells. Generally, it is followed by of cytokinesis, which is the splitting of the cell membrane, thus completing the process of duplicating or dividing the cell.



Binary Fission- is the form of asexual reproduction in single-celled organisms. It is the division of one cell int two cells of the same size. This happens in Prokaryotic cells, as opposed to Eukaryotic cells.


 



But both Binary Fission and Mitosis could both agree that when the cycle is done and there is an error it could result in mutations or even kill the cell.