Protein Flashcards
How much energy does 1g of dietary protein provide?
4 kcal
What is and immunoprotein and give examples of immunoproteins
Inactivating antigens
Examples: Immunoglobulins and antibodies
Explain and give examples of peptide hormone, structural proteins and transport proteins
Peptide hormones - regulate enzyme activity, eg, insulin, thyroid hormone, vasopressin
Structural proteins - e.g. muscle (myosin), connective tissue (collages, keratin)
Transport proteins, e.g. albumin, haemoglobin, transferrin, retinol binding
What are proteins?
Essential for life
Fundamental structural and functional elements of every cell
Protein is the 2nd most abundant chemical in the body
Proteins are macromolecules
Explain structure and function of proteins in the body
They are formed when single units of amino acids polymerise via peptide bond formation
proteins are large, complex molecules that play many critical roles in the body. They do most of the work in cells and are required for the structure, function, and regulation of the body’s tissues and organs
Explain the different roles of proteins and give an example of each
Antibody - Antibodies bind to specific foreign particles, such as viruses and bacteria, to help protect the body.
Example - Immunoglobin G (IgG)
Enzyme - Enzymes carry out almost all of the thousands of chemical reactions that take place in cells. They also assist with the formation of new molecules by reading the genetic information stored in DNA.
Examples - Phenylalanine hydroxylase
Messenger - Messenger proteins, such as some types of hormones, transmit signals to coordinate biological processes between different cells, tissues, and organs.
Examples - Growth hormone
Structural component - These proteins provide structure and support or cells. On a larger scale, they also allow the body to move.
Example - Actin
Transport/storage - These proteins bind and carry atoms and small molecules within cells and throughout the body.
Example - Ferritin
Name places where protein in found
Collagen
Haemoglobin
Myosin
Actin
Name sources of protein in foods
Eggs
Read meat
White meat
Nuts
Dairy
Fish
Benas and pulses
Insects
What is the DRV for protein?
50g
Explain what protein turnover is
Protein turnover is basic property of all human cells
Related to O2 uptake - synthesis requires energy; hydrolysis or peptide bond as well
Rare varies e.g. Albumin = about 20 days
Explain the structure of amino acids
Amino acids = Carbon (C) + Hydrogen (H) + Oxygen (O) + Nitrogen (N) ± Sulphur (S)
They can also contain Phosphorus (P), Iron (Fe), Iodine (I), Magnesium (Mg), Manganese (Mn), Copper (Cu), Zinc (Zn)
Every amino acid has:
Central carbon bonded to a hydrogen
Amino group = NH2
Carboxyl group = COOH
R group (root)
How many amino acids are there in the human body and what category are these classed into?
20 amino acids considered important in human nutrition
Indispensable
Dispensable
Conditionally indispensable
Name and explain the indispensable amino acids
Previously called essential
8 AA’s
Cannot be synthesised by the body
Lack enzymes needed
Must be supplied in the diet
Isolecuine (IIe)
Leuicne (Leu)
Lysine (Lys)
Methionine (Met)
Phenylalanine (Phe)
Threonine (Thr)
Typtophan (Trp)
Valine (Val)
Name and explain the dispensable amino acids
Previously called the non-essential amino acids
3 AA’s
Can be synthesised in the body in sufficient quantity
From carbon skeleton and transamination
Alanine (Ala)
Aspartic Acid (Asp)
Glutamic acid (Glu)
Name and explain the conditionally indispensable amino acids
Previously called conditionally essential
9 Amino acids
Synthesised in the body but insufficient quality or not all the time
Needed under certain conditions including:
Immaturity
Metabolic disorder
Stress
Prolonged TPN (total parenteral nutrition)
