Plasma Membrane & Molecules Flashcards
What are the four main elements found in the human body?
Oxygen, carbon, hydrogen, and nitrogen.
Identify an atoms three particles, their charge and their location.
Electrons (-) are found in the shells outside the nucleus.
protons (+) and neutrons are in the nucleus of the atom
What is a molecule?
A combination of atoms held together by bonds
What is the valence shell? How many electrons can exist within an atoms valence shell?
The valence shell is the outermost level of an Adam that contains electrons they can hold eight electrons
Describe the fluid Mosaic model of membrane structure
Model that proposes that membranes are not rigid with molecules locked into place, but rather consist of proteins that move around within a mixture of lipid molecules that has the consistency of olive oil. Proteins in a fluid lipid bilayer
What is meant by the term membrane asymmetry
Proteins and other components of 1/2 of the lipid bilayer are different from those that make up the other half of the bilateral
What are two major pieces of experimental evidence that support the fluid Mosaic model of membrane structure?
Study done by David Fry and Michael edidin that shows that membranes are fluid.
Experiment that use the phrase facture technique in combination with electron microscopy that showed membrane asymmetry
What is the lipid bilayer made out of?
Phospholipid molecules, each consisting of a head group attached to two long chains of carbon and hydrogen (hydrocarbon) called fatty acids
What is amphipathic?
Refers to the phospholipid by layer. It is a molecule that contains a region that is hydrophobic and a region that is hydrophilic.
What are the 4 key functions of membrane proteins?
- transport
- enzymatic activity
- signal transduction and 4. attachment/recognition
What are integral membrane proteins?
Proteins that are embedded in the phospholipid bilayer
What are the two major classes of membrane proteins?
Peripheral membrane proteins.
And integral membrane proteins
What are peripheral membrane proteins?
Membranes that are positioned on the surface of a membrane and do not interact with the hydrophobic core
What are integral proteins?
Proteins that reside within the hydrophobic core of the lipid bilayer. Usually extend through the bilayer to Span both sides. Has both hydrophobic regions and hydrophilic regions of protein on amino acid chain
What occurs during a dehydration synthesis reaction?
One water molecule is created from two molecules creating a covalent bond. This requires energy. For example the building block used to make protein is amino acid, amino acids are bonded together via a peptide bond.
What are the four levels of protein structure?
- Primary structure
- secondary structure
- tertiary structure and
- quaternary structure
What is the primary structure of a protein?
This is simply the amino acid chain. The sequence of amino acids
What is the secondary structure of a protein?
Results from hydrogen bonding between the amino group of one amino acid in a protein chain with the carboxyl group of another amino acid in the protein chain. Regions of an alpha helix or beta sheet and in some cases a particular loop for coil.
What is the tertiary structure of a protein?
Overall three-dimensional folding of a polypeptide chain.
In many cases, this is the final stage. It occurs due to the interactions between the variable our side groups. Charged amino acids interact and cause folding
What is the quaternary structure of a protein?
This is the interaction of several protein chains, each with its primary, secondary and tertiary structure.
What is the main determinant of a protein function?
Combination of the different structures that produces the final protein and relates to its function
What do you need mutation has occurred, resulting in a change to the primary structure of the encoded corresponding protein. Why am I changing the primary structure change those proteins function? Why might it not change the function?
Primary structure of a protein is the order of the amino acids in the polypeptide chain. Change in amino acid’s may change the charge and effect of the protein folds that’s affecting the function. It’s possible that the charge on the mutation could be the same which would mean there’s no change in folding and no change in function this is called a conservative change
Should also consider that where the amino acid change happens is important as well as the specific amino acid that is changed
What are membrane carbohydrates?
Carbohydrates that are added a short branched chains of monosaccharides to membrane proteins in the membrane lipids.
What do membrane carbohydrates do?
Function in cellular recognition and targeting
What is the function of a carbohydrate?
Carbohydrates are an energy source of carbon to synthesize other molecules ( proteins, lipids etc.)
In terms of the cell membrane, carbohydrates are for signalling and recognition
What are three cellular examples of carbohydrates?
Starch, cellulose, glucose
Describe the structure of a carbohydrate
Contains the elements hydrogen, carbon, and oxygen. With the functional groups hydroxyl and Carbonyl. Have lots of oxygen molecules therefore they are often polar
What is the term given to a monomer of a carbohydrate?
Monosaccharide which means one sugar
How do monosaccharides differ?
Length of the carbon skeleton, location of functional groups, ring structure.
What are the terms given to carbohydrate polymers?
Disaccharides and polysaccharides.
What process is used to create disaccharides and polysaccharides?
Do you hydration is because this creates the sugar chain
What is the bond between monosaccharides called?
A glycocidic linkage
What storage polysaccharide is synthesized by photosynthetic organisms?
Starch.
- Glucose units are bonded in 1,4 glycocidic linkage.
- Helical polymer structure is created
What storage polysaccharide is synthesized in animals?
Glycogen
