Proteins are a polymer, and are used in many areas of organisms. Amino acid monomers are joined by peptide bonds to create a polypeptide that we commonly call a protein. There are around 20 amino acids used when synthesising proteins within an organism. These proteins can be found in different structures, primary, secondary, tertiary and quaternary. The structure of these proteins is decided by the side R-group found on the combination of amino acids.
Thin filaments are one of two types of protein that form myofibrils which extend along the length of the muscle fibers. Thin filaments are formed by three proteins actin, troponin and tropomyosin. The thin filament are twisted to join together forming chains. The thick and thin filament are attached to a Z-line of an elastic protein called titin. The process of movement in a sliding filament mechanism is as follows.
Plays a major role in locomotion, chromosome separation in mitosis and meiosis and intracellular transport of organelles. The cytoskeleton is made up of three kinds of protein filaments: [pic] • Actin filaments (also called microfilaments) They are about 8 nm in diameter, and are thinnest of all cytoskeletal filaments. They are mede up of actin. Actin filaments provides mechanical strength to the cell, links transmembrane proteins (Protein that passes one or more times through the lipid bilayer of a cell membrane) to cytoplasmic proteins. Most actin molecules work together to give support and structure to the plasma membrane and are therefore found near the cell membrane.
Signal transduction happens when a membrane protein may have a binding site with a specific shape that fits the shape of a chemical messenger, such as hormones & other extracellular substances that trigger changes in cellular activity. Another function is cell to cell recognition which occurs when some proteins serve as identification tags that are specifically recognized by other cells. The Cell Wall is a rigid structure mainly made out of the protein cellulose, a tough chemical that helps plants to maintain their shape
This is known as the lock and key model. There is also an induced fit model, which states that the model is not quite as rigid as the lock and key model states. In this model the enzyme may not have an active site that is perfectly complementary to the substrate, but when the substrate collides with the enzyme active site its shape is altered to fit the substrate and make a complex. Enzymes are proteins, the structure of the protein are very important as it give the protein a particular 3-D shape which gives the active site it’s specific shape. The protein structure consists of primary, secondary, tertiary and quaternary structure.
Which include fats, oils, waxes, and cholesterol. They are mostly made up of long chains of monomers. Which is also known as fatty acids. Proteins are polymers made from monomers called amino acids. Which are building blocks of life.
Enzymes are proteins folded into complex shapes that allow smaller specific molecules to fit into them like a lock and key. The place where the substrate molecules fit is called the active site; chemical reactions occur at the active site. Catalase is found in all cells and protects them from a dangerous waste chemical called Hydrogen Peroxide. It breaks the hydrogen peroxide down to water and oxygen The substrate (hydrogen peroxide) and the catalase molecules are continuously on the move. Every so often they will collide so that the substrate molecule(s) fits into the enzyme's active site.
Cristina Alzandua General Biology 1401 Dr. Erin Schuenzel February 13, 2014 Bacterial and Eukaryotic Cell Structures All organisms are composed of cells which are characteristically microscope in size. Cell size is limited by the efficiency of diffusion across the plasma membrane. A typical eukaryotic cell is 10 to 100 micrometers in diameter opposed to prokaryotic cells are 1 to 10 micrometers in diameter. Bacterial and Eukaryotic cells display different cell organization in their size and structure, but despite this all they display basic structural similarities as well. Differences between the structures of a bacterial and eukaryotic cell Bacteria cells are sheathed by a strong cell wall which is composed of peptidoglycan (polymer of sugar).
It control movement in and out of the Nucleus. The nucleolus is found in the nucleus and contains most of the cells genetic material. The chromatin is made up of DNA and proteins. Osmosis is the net movement of water through a semipermeable membrane from areas of a high concentration to areas of low concentrations. Diffusion is the net movement of a substance by the random movement of particles from areas of high concentrations to areas of low concentrations to reach equilibrium.
Structure – The nucleus is encapsulated and protected by the nuclear envelope, which is a double lipid bilayer. Within the envelope is the nucleoplasm, which holds chromatin, a complexity of proteins and DNA, and in the center of the nucleus is the nucleolus. The nucleus also has pores on the outer membrane of the nuclear envelope, which regulate the entry and exit of certain macromolecules (Campbell, 2005, pg.102). Lysosome Function – Lysosomes are membranous sacs filled with enzymes that are used to digest different kinds of macromolecules within a cell (Campbell, 2005, pg.107). Lysosomes are essentially a digestive system for the cell both breaking down materials taken in from outside the cell and breaking down obsolete components of the cell itself (Cooper).