Once a protein source reaches your stomach, hydrochloric acid and enzymes called proteases break it down into smaller chains of amino acids. Amino acids are joined together by peptides, which are broken by proteases. From your stomach, these smaller chains of amino acids move into your small intestine. What causesRead More →
First, an Hsp70 chaperone stabilizes nascent polypeptide chains until protein synthesis is completed. The unfolded polypeptide chain is then transferred to an Hsp60 chaperonin, within which protein folding takes place, yielding a protein correctly folded into its functional three-dimensional conformation. What are the 4 steps of translation? Translation happens inRead More →
The Golgi apparatus receives proteins and lipids (fats) from the rough endoplasmic reticulum. It modifies some of them and sorts, concentrates and packs them into sealed droplets called vesicles. Where does protein sorting and vesicle synthesis occur? From the endoplasmic reticulum, proteins are transported in vesicles to the Golgi apparatus,Read More →
Proteins undergo both cold and heat denaturation, but often cold denaturation cannot be detected because it occurs at temperatures below water freezing. Proteins undergoing detectable cold as well as heat denaturation yield a reliable curve of protein stability. Why proteins denature at high temperature? The denatured protein has the sameRead More →
Neurofibrillary tangles are abnormal accumulations of a protein called tau that collect inside neurons. Healthy neurons, in part, are supported internally by structures called microtubules, which help guide nutrients and molecules from the cell body to the axon and dendrites. What causes plaques and tangles in the brain? When toxicRead More →
Cell membranes are composed of proteins and lipids. Since they are made up of mostly lipids, only certain substances can move through. Phospholipids are the most abundant type of lipid found in the membrane. Phospholipids are made up of two layers, the outer and inner layers. Is glycoprotein a proteinRead More →
The secretory pathway of protein synthesis and sorting. Ribosomes synthesizing proteins bearing an ER signal sequence become bound to the rough ER. … Proteins destined to be secreted move by cisternal migration to the trans face of the Golgi and then into a complex network of vesicles termed the trans-GolgiRead More →
Some hormones that are products of endocrine glands are proteins or peptides, others are steroids. (The origin of hormones, their physiological role, and their mode of action are dealt with in the article hormone.) What are hormones made of? Hormones can be grouped into three main types: amines, these areRead More →