Lab 3 Concepts + Vocab

Structural proteins

their primary role is to form and maintain the shape of cells or cell structures

Membrane transport

this type of protein is required to move certain substances from one side of a cell membrane to another

Regulatory protein/transcription factor

genes are turned on or off by these proteins

Immunoglobulin (antibodies)

some immune system cells produce these proteins that bind to pathogens and mark them for destruction

Signal molecules

this type of protein, secreted by one cell and binding to another, serves an important role in cell-to-cell communication

Receptors

These proteins bind signal molecules and begin the process that leads to a cellular response

Binding protein

this type of protein specifically attaches a ligand and moves it from one location in the body to another

Enzyme

This type of protein speeds up the rate of chemical reactions

Binding site/Active site

specific area where the ligand and protein bind

→ Ex: receptors must have a specific _____ for a signal molecule, regulatory proteins must bind to a specific DNA sequence in the nucleus, binding proteins must have a specific _____ for what they are transporting around the body, etc

Modulation

something that stimulates an increase or decrease in the activity of a protein

→ there are chemical and environmental modulators

Chemical modulators

bind to or alter the make up or shape of the protein to change its activity level

→ Proteolytic activators and inhibitors

→ Allosteric activators and inhibitors

→ Covalent activators and inhibitors (Phosphate or other functional groups added or removed)

→ Competitive inhibitors

→ Co-factor activators (also called co-enzymes): derived from vitamins and minerals

Environmental modulators

include pH and temperature, which alter the shape and therefore the activity of proteins

Optimum pH and temperature

each protein has this, at which it achieves its highest rate of activity and performs the most work

Ligand/Substrate

enzymes like amylase bind to and act on this

An enzyme and its substrate fit together in a lock and key fashion….

they must fit together perfectly in order for the interaction to take place

Starch (amylase) → Maltose + Maltotriose

Chemical reaction catalyzed by amylase

Starch (carbohydrate, polysaccharide)

What are the substrates in the chemical reaction?

Maltose (disaccharide, glucose) and Maltotriose (oligosaccharide)

What are the products in the chemical reaction

Salivary Amylase

Enzyme used in the chemical rxn

Starch activity is high, amylase activity is low

Dark blue color indicates…

Starch activity is low, amylase activity is high

What does an orange color indicate?

• Names end in “ase” (most)

• Speed up chemical reactions by lowering the activation energy

• Are proteins

• Can be modulated

• Can be re-used

• Act on specific substrates

• Names often reflect what they do and what they act on

• Not changed by the chemical reaction

• Facts about enzymes