realizată de izabella woodhouse 17 zile în urmă
61
Proteins Concept Map
realizată de izabella woodhouse 17 zile în urmă
61
One of the functions of proteins is as signaling molecules in the body. signals can travel from one cell to another, or across the whole human body through the bloodstream
body’s biochemical response to stress
These signals belong to two main systems in the body: the endocrine system and the nervous system.
a chemical structure produced by cells that binds to another biological molecule (These are also proteins)
Where and how hormones and neurotransmitters act on cells depends on the polarity of the chemical signal molecule
one hormone molecule can activate many second messengers - large affect from small signal
chemical signals include proteins and modified amino acids.
Hydrophilic proteins and amino acids are water loving molecules. However they are not able to pass through the lipid bi layer of a cell membrane. This causes them to use a receptor as there way in which adapts to the hormone or protein and then allows for a secondary messaging or signalling system to take place usually with cAMP.
These reactions are fast but not long lasting.
ex. insulin, epi, glucagon
only cells with the right receptor respond to a given hormone
chemical signals include modified amino acids, like the hormone thyroxine, and also lipids molecules called steroids (a type of non-polar lipid molecule consisting of 4 carbon rings fused)
these are non-water soluble molecules that can pass the cell membrane. they directly work with the DNA to work out the continuance or stop to the development of proteins and other instructions. Regulates gene transcription and protein synthesis.
a chemical substance produced by nerve cells that stimulates or inhibit other nerve cells
Dopamine is a neurotransmitter produced by neurons in the nervous system that send and receive signals
a chemical substance produced in the body that regulates and controls the activities of certain cells or organs
Adrenalin is a hormone that is produced by glands in the endocrine system and sends chemical signals
Storage proteins store nutrients and energy-rich molecules for later use
Ex. Ovalbumin is the main storage protein in egg whites. It provides an energy source to the growing bird embryo
Defense proteins help organisms fight infection, heal damaged tissue, and evade predators
Ex. Fibrin proteins form blood clots and scabs at a wound site. Fibrin is a sticky, rope-like protein that plugs a wound and stops the bleeding
Motor proteins keep cells moving and changing shape.
They also transport components around inside cells
Ex. Dynein and kinesin carry vesicles and other cargo around the cell. They walk along tiny microtubule "highways."
Sensory proteins help us learn about our environment
They help us detect light, sound, touch, smell, taste, pain, and heat
Some organisms can even detect electricity or magnetism
Ex. Opsins in the eye detect light. They convert light into electrical and chemical signals that can be interpreted by the brain
Transport proteins move molecules and nutrients around the body and in and out of cells
Ex. Hemoglobin in red blood cells picks up oxygen from the lungs and delivers it to all the tissues in the body
Regulatory proteins bind DNA to turn genes on and off
Active genes are used to build proteins
Ex. The p53 protein prevents a cell from dividing when its DNA is damaged. It prompts the cell to repair the damage or self-destruct (apoptosis)
Signaling proteins allow cells to communicate with each other
Signals, receptors, and relay proteins work together to get information from the outside of a cell to the inside
Ex. Insulin is released into the blood stream after a meal. It activates the insulin receptor, which signals muscle and fat cells to store blood sugar.
Help strengthen cells, tissues, organs, and many more
Ex. Collagen strengthens our bones, cartilage, tendons, ligaments, and skin. It makes up about a quarter of the body's total protein
Tubulin forms hollow tubes, called microtubules, that support the structure of the cell.
Build and break down molecules.
Critical for growth, digestion, and many other cellular processes
With out enzymes chemical reactions would occur too slow to sustain life
Ex. lactase helps babies digest and break down the lactose and other sugars in breast milk
Amino acids, the monomer of proteins, have a common chemical structure.
The amino acids link up into a linear chain of amino acids similar to how monosaccharides link up in carbohydrates.
In carbohydrates this structure is called a polysaccharide, so similarly in protein we use the term polypeptides.
Amino acids come together to form a poly peptide chain and each individual part of the chain is called a peptide.
This happens through dehydration synthesis which is when the oh and h from the carboxyl group and amino group come together through condensation and release the water and instead form a covalent bond which is called a peptide bond
As the two peptides are brought together with the peptide bonds sides facing each other the polar functional groups on opposite peptide will attract to each other with strong hydrogen bonds which is how the secondary structure is formed.
Some proteins will only function when they are combined with another protein sub unit creating a quaternary structure.
These include enzymes, microtubules, actin, myosin, and hemoglobin
Actin and myosin are especially important because they can change shape to allow parts of a cell or whole organism to move
In muscle cells, myosin uses energy to pull actin fibres together allowing muscle tissue to contract.
the tertiary structure is the second last configuration of the polypeptides which is when all the R groups interact. Many proteins don't function until they are in this stage of structure.
Remember that the R groups of a peptide are the only part that is going to be different.
During this stage the different characteristic of the protein directly correlate to its shape and function.
Works with polar and non-polar, negative and positive.
The structure of a protein fits its function
If you change the shape of it like add heat or something it damages it making it not work anymore. This is called de-nature when it folds apart and stops working.
In peptide bonds there are 2 polar functional groups:
The amino group (-NH)
The Carbonly (-C=O)
As the two peptides are brought together with the peptide bonds sides facing each other the polar functional groups on opposite peptide will attract to each other with strong hydrogen bonds which is how the secondary structure is formed.
Secondary Structures are the next configuration of the amino acids which link up together by the carboxly group forming a polypeptide chain.
The important parts of this secondary structure is the formation and presence of a-helix and b-sheets.
Alpha- helix shapes are like a spiral that are bonded by strong hydrogen bonds.
Beta- sheets are like 2 rods side by side also held together by hydrogen bonds.
primary structures are the first structures the polypeptides will become. This is in a linear form where the amino acids or peptides are written out in a line.
Each peptide will consist of a Carboxly, Amine, and R group. The R group is the only part of the protein or peptide that will change creating the different proteins on the chain.
