Proteins - variety Flashcards
What is the basic structure of a polypeptide chain?
20 naturally occurring amino acids
How much can the length of polypeptides vary?
From a few to thousands of amino acids
What determines the number and order of amino acids in a polypeptide?
The genetic code (DNA base sequence)
What role do enzymes play in proteins?
Speeding up cellular reactions (catalysis)
What is the role of blood proteins?
Interact with oxygen to form a gel-like scab across a wound
What are the strengthening fibers in skin, hair, and tendons?
Collagen and keratin
What vital metabolite is carried by haemoglobin?
Oxygen
What is the cytoskeleton’s function?
Network of tubules that cause chromosomes to move during the cell cycle
What is the function of hormones?
Chemical messengers that affect other parts of the body
What proteins compact DNA in chromosomes?
Histone proteins
What is the immune response’s most diverse group of proteins?
Antibodies (immunoglobulins)
What type of proteins determine which substances can pass across a membrane?
Membrane transport channel and carrier proteins
What is the shape of immunoglobulins?
Generic ‘Y’ shape
What is Rubisco?
An enzyme that catalyses the fixing of CO2 during photosynthesis
How many polypeptide chains compose Rubisco?
16 polypeptide chains
What is the primary function of insulin?
Causes absorption of glucose from the blood
How many polypeptide chains compose insulin?
2 polypeptide chains
What is rhodopsin?
A pigment in the retina that sends nerve impulses to the CNS
What is collagen’s role in the human body?
Forms a network that resists tearing forces
What is unique about spider silk?
As strong as steel wire but lighter
What helps spider silk resist breaking?
Coiled parts that stretch under tension
Fill in the blank: Rubisco is considered the most important enzyme in _______.
nature
What is the average length of a protein?
300 amino acids
