RAT #1 Flashcards
Covalent bond
1 Atoms share electrons
Strongest type of bond
Ex - Carbon atoms in glucose
Ionic bond
2 Opposite ions are attracted to each other i.e. NaCl
Hydrogen bonds
3 A weak attraction between a hydrogen atom and a nearby O, N, or F atom i.e. attraction between water molecules
Note - bonds that are within a water molecule are covalent
Van der Waals forces
4 Weakest type of attraction, non specific interaction between the nucleus of one atom and the electrons of another - allows molecules to pack close together.
“like dissolves like”
Ex - phospholipid molecules
Why is van der waals forces weak?
Because if the atoms get too close their electrons repel each other.
LO Define homeostasis
Body’s complex maintenance of ideal physical conditions. Ex: maintain blood pressure, blood pH, glucose levels
LO Describe a simple homeostasis loop
A controlled variable is monitored by a sensor, which reports to an integrating center (usually central nervous system). The integrating center processes info and sends out signals (usually via nerves or hormones) to the effector tissues to correct the problem.
Plasma membrane
A flexible barrier that holds cell shape.
Phospholipid bilayer with cholesterol molecules throughout
Proteins on the inside/outside surface that are important in recognition
Nucleus
DNA is transcribed into mRNA here, which is then translated into proteins in the cytosol.
Contains nucleolus that synthesizes proteins
Mitochondria
Powerhouse of the cell (most ATP is produced here)
Contains (co)enzymes important in the krebs cycle and electoral transport chain
Rough endoplasmic reticulum
Ribosomes cover this folded structure. Translation of mRNA to make proteins that will be exiting the cell take place here
Proteins translated by free Ribosomes will stay in the cell
Smooth endoplasmic reticulum
Steroid hormone and lipid synthesis (anabolism) and break down (catabolism), site of calcium storage and calcium release based on cell activity
Golgi apparatus
Folded membrane that is the “finishing school” for proteins that are to be exported out of the cell.
Membranous organelles include
Mitochondria and golgi
Which cell structures/functions involved microtubules
Cilia, moving molecules from one pt of the cell to another, flagella, mitosis
Which is not a membranous bound organelle made from insoluble protein fibers
Polyribosomes
Cells that secrete large amounts of protein would most likely possess larger numbers of or an extensive network of ______.
Ribosomes, golgi, RER
LO Leaky Junctions
Lots of traffic between cells ex between heptocytes (liver cells)
LO Tight Junctions
Junctions that restrict the movement of materials between the cells they link
Barrier properties of tight junctions are dynamic and can be altered depending on the body’s needs
LO Adherens Junctions
Link actin fibers in adjacent cells together
“strength” ex-myocardiocytes
LO Gap junctions
The simplest cell-cell junctions
Allow direct and rapid cell to cell communication through cytoplasmic bridges between adjoining cells.
Connected by connections to create passageways that look like hollow rivets with narrow channels through their centers (channels are able to open and close, regulating the mvmt of small molecules and ions)
LO Define an ion
A charged atom/molecule charged because number of protons in nucleus does not equal number of electrons