Biology Notes

Chapter1

Proteins

A. Proteins are vital for growth and repair. B. For sending signal from one cell to another C. Catalyzing chemical reactions D. Regulating hormones E. Moving muscles

Proteins are polymers- ammino acids joined together by polypeptide chains.

- Made up of S, P, C, O, H, N. - Ammino acids are made up of a carboxyl, anime group and a variable

attached to a carbon atom. - Only 20 ammino acids are there - 4 types of proteins: Primary, Secondary, Tertiary and Quaternary.

Types in Depth:

Primary: linear sequencing of ammino acids. Slight changes in the chain can cause huge problems.

Secondary: Proteins created through hydrogen bonding in a polypeptide chain. Folds either into alpha helix or a beta pleated sheat. These are refered to fiborous proteins ( wool, reptile scales, human hair outer appearences.

Tertiary: tertiary structure will have a single polypeptide chain "backbone" with one or more protein secondary structures, the protein domains. The tertiary structure is determined by a variety of bonding interactions between amino acid side chains.( Multiple secondary proteins if hydrogen bonding)

Quaternary: More than one polypeptide chain. Hemoglobin for example.

Portein Folding: - Denaturation is when weak intramolecular forces cause proteins to lose their

shape.

- Chaperoin porteins assist in folding other porteins which determine protein functions.

- Prions are proteins that result in misfolded protentins.

Nucleic Acids: - RNA and DNA encode hereditary information. RNA send info to the DNA,

which is used to manufacture ammino acids for proteins. Nuclecid acids consist of nucleotides.

- Nucleotides are made up of a phosphate, a 5-carbon sugar and a nitrogen base.

Functional groups: Organic chemicals replace hydrogen atoms that would have been present in hydrocarbons.

Gibb’s free energy: If energy is released it is exothermic, and if energy is absorbed it is endothermic.

Metabolism is the total number of chemical reactions that are taking place in a cell. Catblolism reactions break down molecules and anabolism builds up molecules in the cell. The Metabolic reactions happen in pathways that are sped up by enzymes. Enzyems reduce the amount of the activation energy needed to speed up reactions. The transition state is the unstable state after energy has been absorbed to initate the reaction.

Enzymes: Enzyme’s are global

The Cell

- Theory of endosymbiosis states that prokaryotic cells such as mitochondria and chloroplasts merged into larger cells.

- Modern theory states that all living organism are made up of cells and all cells arrived from previous cells.

- All cells have permeable membranes, Cytosol, and Ribosomes to create DNA - Prokaryotic cells have a nucleoid that isn’t bound by plasma membrane that

contains chromosomes there, and doesn’t have internal memebranes. Eukaryotic cells have nucleus with plasma double membrane and internal membranes for organelles ( in order to specialize the chemical reactions).

- The function of a cell dictates it’s form ( the shape that it takes). - Cells are determined by their volumes and surface area. Because the cells

volume determines metabolic activity, millions of cells are made in large organisms to undertake a lot of metabolic activity. Surface are controls what comes in and out of a cell.

- Nucleolus: Place where Ribosomal RNA is synthesized according to instructions from the DNA. Also where some ribosome units are assembled. Nucleolus takes proteins from cytosol and combines it with rRNA made in the nucleolus.

-