Lecture 4 Flashcards
(41 cards)
Organic molecules; What do proteins do?
They give structural support, facilitate chemical reactions by acting as a catalyst. They do practically everything. They typically make up 50% of organic matter in an animal body.
Organic molecules; What do nucleic acids do?
They encode & transmit, and store genetic information. There are two types of nucleic acids; DNA and RNA, which are different in structure and function.
Organic molecules; What do carbohydrates do?
They provide a source of energy and make up a cell wall in; bacteria, plants and algae.
Organic molecules; What do lipids do?
They make up the cell membranes, they store energy and act as signalling molecules.
Most organic molecules are what? (think of monomers together)
Polymers, which are made up of monomers (single units) that are covalently bonded to make polymers. A polymer is essentially a chain/ring of monomers.
How do you build polymers?
Through dehydration synthesis or a condensation reaction which means the same thing. It basically means the removal of H2O to make a longer polymer.
How do you break down polymers?
Through a hydrolysis reaction which means the addition of H2O to make a smaller polymer.
What are 8 different types of proteins?
- Enzymatic proteins
- Defensive proteins
- Storage proteins
- Transport proteins
- Hormonal proteins
- Receptor proteins
- Contractile proteins
- Structural proteins
Types of proteins; What are Enzymatic proteins?
Selective acceleration of chemical reactions, like digestive enzymes are used as a catalyst to quicken the hydrolysis of bonds in food molecules.
Types of proteins; What are defensive proteins?
They’re used to protect the body against diseases, like antibodies since they inactivate/help destroy viruses & bacteria.
Types of proteins; What are storage proteins?
They store amino acids, like plants have storage proteins in their seeds. Also, ovalbumin is the protein in an egg white, which is used as an amino acid source, which would be used to develop an embryo.
Types of proteins; What are transport proteins?
They transport substances, like hemoglobin which is a protein of vertebrate blood that contains iron. It transports oxygen from the lungs to other areas of the body. Another example would be other proteins that transport molecules across cell membranes.
Types of proteins; What are hormonal proteins?
They coordinate an organisms’ activity, like insulin which is a hormone that’s secreted by the pancreas. Insulin causes other tissues to take up glucose, which regulates blood sugar concentration.
Types of proteins; What are receptor proteins?
It’s the response of a cell responding to chemical stimuli, like receptors in the membrane of nerve cells, which detect signalling molecules that are released by other nerve cells.
Types of proteins; What are contractile proteins?
Their function is to move, like motor proteins are responsible for the undulations of cilia and flagella, etc. In addition, another example would be Actin and Myosin proteins, which are responsible for the contraction of muscles.
Types of proteins; What are structural proteins?
They’re for support, like collagen and elastin proteins which provide a fibrous framework in animal connective tissues.
In proteins, what are the monomers? Explain a bit.
Amino acids.
Monomers compose polymers, just like amino acids compose proteins. The links between amino acids (monomers) are covalent bonds (in this case=peptide bonds).
What are the covalent bonds between amino acid called? Explain them a bit.
Peptide bonds, which are formed through a condensation reaction since it generates water. These peptide bonds specifically occur between an amino acid from the amino group and one amino acid from the carboxyl group.
What’s a dipeptide?
It’s a molecule made up of two amino acids.
What’s a polypeptide?
It’s a molecule made up of more than two amino acids.
What’s the primary structure of a protein?
It’s a sequence of linked amino acids which are linear-ly linked. Each protein has a different (unique) sequence of amino acids. Proteins are always “read” from N-terminus to C-terminus.
What’s the secondary structure of a protein?
There are interactions between stretches of amino acids that lead to the formation of a helix and B sheets. These interactions are between the carboxyl group (in one peptide bond) and the amide group (in another peptide bond). There interactions are the formation of H-bonds which are the backbone of amino acids (not R groups).
What’s the tertiary structure of a protein?
It’s a 3D configuration of one polypeptide chain, usually made of various secondary structure components. It’s determined by the spatial distribution in the molecule of hydrophilic “R groups” and hydrophobic “R groups”. Ultimately it determines the function of the protein.
Tertiary structure of a protein; What are hydrophobic amino acids?
They cause the polypeptide to fold.
