Bio/Biochem: Enzymes and Stuff

Ligase

Join molecules together, typically requires an ATP

Starvation

Leads to increased plasma cortisol, inability to undergo thermogenesis, unrestrained appetite, and resistance to insulin.

Why is mitochondria maternal?

During fertilization, the sperms mitochondria disintegrates

Transduction

The process whereby genes are transferred by a virus

Transformation

Bacteria take up DNA from surroundings, the media they are immersed in

Conjugation

Requires pious and separate set of genes present on a plasmid called a (F)ertilty Factor

Positive pressure ventilation

It is mechanical, you use either a breathing machine (ventilator) via ET tube or non-invasive bag-mask, CPAB, BiPAP, etc to force air into the lungs, expand the lungs and deliver oxygen to the alveoli.

Diffusion

of gases is important in the movement of oxygen into the blood from the alveoli and the movement of carbon dioxide out of the blood into the alveoli

Negative pressure ventilation

Mammals use this method to suck air in. The diaphragm contracts and move down, the intercostal muscles contract and move up and out. This causes the lungs to expand. The pressure inside the lungs drops

Microfilaments

Are also called actin filaments

Actin filaments

Microfilaments: involved in motion and movement. Can act as highways inside the cell for the transport of cargoes, including protein-containing vesicles and even organelles. It can also be used in cell division for cytokinesis.

Intermediate filaments

more permanent and play an essentially structural role in the cell. They are specialized to bear tension, and their jobs include maintaining the shape of the cell and anchoring the nucleus and other organelles in place.

Microtubule

is made up of tubulin proteins arranged to form a hollow, straw-like tube, and each tubulin protein consists of two subunits, α-tubulin and β-tubulin.

Microtubules

are dynamic structures: they can grow and shrink quickly by the addition or removal of tubulin proteins

Microtubule structures

flagella, cilia and centrosomes.

Gap Junctions

essentially tubes that join two cells together. These tubes create a connection that allows for the transport of water and ions to and from the connecting cells. The tubes also help to spread electrochemical signals that are produced by action potentials that occur in the nervous system (neurons) and in cardiac cells that make your heart beat

Tight Junctions

The cell membranes are connected, but the contents of each cell are not connected in any way. There are no tubes here, but there is an impermeable layer in between the cells. These types of cell connections are useful in places that need to contain certain fluids, like in the bladder, the intestines or the kidneys.

Desmosomes

cell membranes are connected by thread like substances that connect the cells across the space in between cells. Do not allow materials/ fluids to pass from one cell to another.

Isomerase

Rearranges the to the other enantiomer

Lyase

Breaks compounds apart

Hydrolase

Breaks compounds apart via water

Oxid0-reductase

Transfers electrons (Redox)

Transferase

Transfers functional groups (ie kinase)

Vmax

Maximum rate at enzyme saturation

Km

Substrate concentration at ½ vmax

closer to 0

Which has a higher Km value

Lower y-intercept

Which has a higher Vmax

Competitive inhibitors

Increase km, doesn't change vmax

Non-competitive inhibitors

Doesn't change km , decrease vmax

Uncompetitive inhibitors

Decrease km, decrease V max -parallel

Mixed inhibitors

Two options - both decrease vmax

Inhibitor prefers binding to enzyme -substrate complex

Decrease Vmax, decrease km

If inhibitor prefers binding to enzyme alone

Decrease vmax, increase km

Cofactors

Generally inorganic molecules, metal ions, and are often ingested as dietary minerals

Coenzymes

Small organic grapes, and the mass majority of which our minerals are derivatives of vitamins, such as NAD+,FAD, and coenzyme a

Apoenzymes

Enzymes without their cofactors

Holoenzymes

Enzymes with their cofactors

Prosthetic groups

Tightly bound cofactors/coincides that are necessary for enzyme function

Catalytic efficiency

kcal/Km, how well an enzyme converts substrate to product

Hills coefficient

>1; positively cooperative binding

Substrate to product in unit time

Kcat means the turnover rate, what does that mean?

Kcat/Km

Catalytic efficiency

Catalytic efficiency

measure of an enzyme’s specificity for a particular substrate.

Vmax/[E]

Kcat