Lecture 5: Flashcards
Side chains:
(R groups) determine the folding shape of a protein, changes in amino acid can change the protein structure- change functionality of the protein
denaturing proteins:
quaternary structure is destroyed: amino acid sequence is intact, but loses functionality. Whipped cream= mechanical disruption (physically changing) cooking eggs= heat disruption. changing the pH with baking soda or salt= melts hydrogen bonds.
nucleic acids (polymer)
nucleotides: a molecule with three parts= 1) three carbon sugar (ribose and deoxyribose) 2) phosphate group 3) nitrogen containing base. DNA and RNA, the molecules of hereditary, are nucleic acids. nucleic acids= polymers of nucleotides, formed by dehydration synthesis between nucleotides. deoxyribonucleic acid (DNA) can contain million of nucleotides, two strands that form a double helix and are linked by hydrogen bonds, it forms genetic material of all cells, the sequence of deoxyribose nucleotides spell out genetic information needed to construct proteins. Ribonucleic acid (RNA)= a single strand of ribose nucleotides, it is copied from DNA, it directs protein synthesis, remember those cool ribozymes from early life?. Changes in the Yuletide bases of lactase gene-change in amino acid-change in protein shape- change in functionality- lactose intolerant. ATP is a nucleotide too: adenosine triphosphate is ribose nucleotide with an adenine based and three phosphate groups, it is formed by reactions that release energy such as the breakdown of sugars. ATP stores energy in the bonds among its phosphate groups, the energy is released when one of those bonds is broken, this energy drives many different type of reactions.
carbohydrates- function
dietary energy, storage plant structure. compound: monosaccharides examples: monosaccharides=glucose, fructose. disaccharides= lactose, sucrose. polysaccharides= starch, cellulose
lipids- functions:
long term energy storage (Fats), hormones(steroids).
the nucleus:
the nucleus is separated from the cytoplasm by a double membrane (lipid bilayer x2) called the nuclear envelope. pores in the envelope allow certain materials to pass between the nucleus and the surrounding cytoplasm. RNA, nucleolus products.
nucleolus:
inside nucleus, makes pieces of ribosomes.
neuron response to taking drugs:
polar, hydrophilic system. receptor is protein-interacting with drug GDP-GTP dehydration reaction. cell machinery is activated to copy DNA code for making more ion channels to compensate for the overwhelming signal from drug.
cell structure and function:
Robert hooke coined “cells” in 1600s: thought they looked like jail cells in cork.
the first microscopes:
zacharias Janssen and sons in 1595 in holland. Magnification 3x-9x. Antony can Leeuwenhoek (1632-1723): built practical microscopes, capable of magnification- 200x, historically the first person that observed live cells under the microscope, curious-looked at EVERYTHING
unifying properties of cells:
smallest self sustaining unit of life. organization. replication. energy transformation and exchange. regulation of internal environment. communication with other cells.
Matthias schneiden (botanist) and Theodore Schwann’s (zoologist) contributions:
cell are basic living units of organization and function, all organisms are composed of cells.
Rudolph virchow contributed:
all cells come from other cells.
two major categories of cells:
1) prokaryotic- bacteria, archaea. prokaryotes appeared about 3.5 billion years ago. 2) eukaryotic-protists, plants, fungi, animals. Eukaryotes appeared about 2.1 billion years ago. basic common features= all bounded by a thin plasma membrane, thick jelly like fluid called the cytosol inside, suspends all cellular components, protein based filaments in cytoplasm that maintain the structure of cytoskeleton, all cells have one or more chromosome carrying genes made of DNA, all cells have ribosomes, tiny structures that build proteins according to the instructions from the genes
prokaryotic layer structure:
outside-in. capsule for protection and “stickiness”- firbriae/pili also help cell attach, flagella help cell move. cell wall protects and keeps shape. plasma (cell) membrane surrounds cytoplasm and cell machinery.
the prokaryotic cell inside organization:
plasma membrane: encloses cytoplasm. Ribosomes: synthesizes proteins. nucleotide: contains single circular bacterial chromosome called Plasmid. Region in cytoplasm not an organelle
eukaryotic cells are more complex:
organelles: membrane bound structures that perform a specific function. double membrane bound nucleus, houses cells DNA. Plant cell specialty: chloroplasts, cell walls, vacuoles. Animal cell speciality: lysosomes.
