Proteins Flashcards
What based on amino acids are grouped? Name 4 groups
Based on amino acid side chain: 1) electrically charged 2) polar uncharged side chain 3) special cases 4) hydrophobic side chain
Describe secondary protein structure.
Exists 2 folding patterns: a-helix and b-sheet. Local folding patterns stabilized by hydrogen bonds between the backbone atoms of amino acids.
Describe tetrarchy protein structure.
mutual position of secondary
structures to space. The tertiary structure determines the protein’s specificity and functionality.
Quarter protein structure.
tertiary structure with other bonds (hydrogen bonds, S-S
bonds, gravitation powers etc.) or with bounded non-proteins
compounds – metals, phosphate etc.
Hidrophobic interactions. Where can they occur?
These interactions often take place between amino acids with nonpolar side chains (and doesn’t form hydrogen bonds with water molecules). Between leucine and isoleucine, two valine amino acids.
Where does s-s bond occur?
Between two side chains of cysteine amino acids in a protein.
What are two natural quarter structures for proteins?
Globular (soluble in water) and fibrillar (not)
What is recommended protein intake per kg?
about 1,0 g proteins / kg of body weight/day
What happens if you consume excessive amount of protein?
Higher amount is utilized as energy source after
deamination. The excessive intake of proteins entails problems for liver and kidneys.
How Mailard reaction can affect nutritional value of foods?
Destruction of essential amino acids (Lysine,
Cysteine, Methionine, Tryptophan, Tyrosine)
Destruction of some vitamins (ascorbic acid,
pyridoxin, thiamine)
▪Worsened the digestability of proteins
▪Deactivation of enzymes
Mailard reaction on bread process
Mailard reaction happens between sugars available and gluten (protein) when in baking bread (crust forming)
What are essential amino acids?
Organism cannot synthesized it and must it intake
from food.
Valine, leucine, isoleucine, methionine,
tryptophan, phenylalanine (aromatic)
What does limiting amino acid mean?
AA which limited proteosynthesis range in liver.
When during proteosynthesis all molecules of
limiting AA are used,
proteosynthesis is stops,
and other rest amino acids are used as energy
source;
What does AAC stand for?
Amino Acid Score. This is a measure used to assess the quality of a protein based on its amino acid composition relative to human nutritional needs.
EAAI stands for?
Essential Amino Acid Index - EAAI. it conveys dependency of proteosynthesis range on
the relative total content of EAA.
