Item 3 Flashcards
There are approximately 10 _ cells in the human body, or 10^14
10 trillion
Cells are physically linked by _ _
gap junctions
In most instances, cells communicate through _ _
chemical messengers
Gap junctions link adjacent cells and are formed by _, plasma membrane proteins
connexins, which form structures called connexons
T OR F: connexons form connexins
false - connexins form connexons
Most often, cells communicate via chemical messengers in the form of _, molecules that bind to proteins reversibly
ligands
Free-floating _ exist in the cell
ribosomes
Primary _somes are in the cell
primary lysosomes
Cytosol is found in _CF
ICF
Hydro_ phosphate heads interact with fluid on both the ICF and ECF sides of a cell, whereas hydro_ tails exist between them
hydrophilic phosphate heads (like water) vs hydrophobic fatty acid tails within (keep a water barrier)
The _ apparatus is in a cell
Golgi apparatus
The _ is the powerhouse of a cell
mitochondrion
The _ surrounds the nucleolus
nucleus
The cell contains _ _ reticulums
smooth endoplasmic reticulums
Are carbohydrates generally polar or nonpolar?
polar
Are triglycerides polar or nonpolar?
nonpolar
What two speciaized structures can phospholipids form in an aqueous environment?
Micelles
_
phospholipid bilayer
Phospholipid bilayers and micelles each contain lipid layers of phospholipids aligned such taht polar heads face the _ _ and the nonpolar tails face _ _
aqueous environment; each other
Phospholipid bilayers have both a polar region and a nonpolar region, and are said to be _ molecules
amphipathic molecules
Glycogen is composed of subunits of _
glucose
Proteins are composed of subunits of _
amino acids
Nucleic acids are composed of subunits of _
nucleotides
_ _ function in the storage and expression of genetic information
nucleic acids
_ helps build and repair cells and body tissues, including the skin, hair, muscle, and bone. _ [same] is also important for blood clotting, immune system responses, hormones, and enzymes
protein
_ is used to store energy without exerting an osmotic force that would draw water into the cells, making the cells swell and possibly burst. A single large storage molecule will not draw in nearly as much water
glycogen
The four types of chemical interactions responsible for tertiary protein structure in the order of their strength of bonding:
hydrogen bonds - form between polar R groups
ionic bonds - form between ionized or charged R groups
van der Waals forces - electrical attractions between the electrons of one atom and the protons of another atom
_ _ - form between the R groups of two cysteins
covalent bonds
Weak chemical interactions between R groups are easily disrupted by changes in pH or temperature with a process called _
denaturation
Disulfide bridges, covalent bonds that provide a strong chemical interaction between protein R groups, are critical to the structure of antibodies and to the structure of the hormone _
insulin