Exam 1: Cells and Chemistry

list the membrane-bound organelles

nucleus

mitochondrion

endoplasmic reticulum

ribosome

golgi apparatus

lysosome

peroxisome

nucleus parts

nuclear envelope

nuclear pores

chromatin

nucleolus

nuclear envelope

encases the entire nucleus

two thin layers separated by fluid

nuclear pores

allows for the passage of proteins, RNA, and solutes through the nuclear envelope

chromatin

condensed DNA intermixed with proteins

allows for storage of a lot of information in a small area

nucleolus

site of ribosome synthesis

nucleus purpose

stores DNA and is site for DNA replication

rough endoplasmic reticulum

dotted with ribosomes

synthesizes and modifies proteins

smooth endoplasmic reticulum

lacks ribosomes

synthesizes lipids (phospholipids, hormones) and some carbohydrates

high quantities in reproductive cells because of hormone production need

golgi apparatus purpose

stores, modifies, and ships products from the ER

close to ER because the “factory” needs to be close to the processing site

golgi apparatus faces

cis face - facing the ER, receives transport vesicles from the ER

trans face - facing away from ER, sends secretory vesicles within and outside of the cell

mitochondria

site of ATP synthesis and storage

high quantities in muscle cells

mitochondrion parts

outer membrane - protects and controls what comes in and out

matrix - where the middle 2 steps of cellular respiration occur

inner membrane - lots of folds to increase surface area for ATP production

lysosome

recycling and garbage disposal center

breaks down and reuses unneeded or damaged cells via enzymes

breaks apart pathogens

enzyme

proteins that promote reactions

can both break things apart and put things together

peroxisome

purification center

lipid metabolism (breakdown and absorption)

detoxification of pathogens and toxins

non-membrane-bound cell parts

plasma membrane

motile structures

microvilli

cytoskeleton

cell junctions

plasma membrane purpose

protects cell from external environment by being selectively permeable

keeps what it doesn’t want out, and lets in what it does

plasma membrane structure

phospholipid bilayer

phosphate heads that are hydrophilic

lipid tails that are hydrophobic

glycoproteins

component of plasma membrane

protein with a carbohydrate attached

protrude out of bilayer for cell-cell communication

glycolipids

component of plasma membrane

lipid with a carbohydrate attached

cell-cell communication

partially done by glycoproteins and glycolipids

making sure that cells next to it and immune system receive signals about the cell’s health and what it needs

location types of membrane proteins

integral proteins - go through the entire membrane, can be hollow or solid

peripheral proteins - only on one side of the membrane

functional types of membrane proteins

channel

anchor

receptor

enzyme

channel proteins

a type of integral protein that allows materials to pass through

anchor proteins

keep cells together

receptor proteins

send signals to nearby cells or molecules

enzyme proteins

break apart large molecules so we can digest individual parts

cholesterol

component of the plasma membrane

lipid precursor (starting unit) to most lipid-derived hormones needed for chemical signaling in the body

contributes to stability of the phospholipid bilayer and anchoring it in different directions

motile structures

provide mobility to cells

flagella (only on sperm)

cilia - many small hair-like structures that can move the cell itself and move other things away from the cell

microvilli

small finger-like membrane protrusions that increase surface area

increases all types of interactions with chemicals

highly concentrated in small intestine

cytoskeleton

groups of fibrous proteins that give stability to cells or connects cells

microtubules and microfilaments

cell junctions

connections between the membranes of adjacent cells

tight, gap, and anchoring

tight junctions

sealed connections that prevent fluid and molecules from getting through

ex: bladder - keeps fluid from leaking out

gap junctions

a passageway between cells that allows for fast movement of fluid, molecules, and signals

rapid communication and coordinated actions

ex: cardiac and smooth muscle cells

anchoring junctions

influences shape and folding of adjacent cells, stabilizes and anchors them

ex: epithelial and endothelial cells like arteries of the heart (need to resist pressure)

homeostasis

the state of steady internal conditions maintained by living things

what helps maintain homeostasis

feedback loops (mostly negative) which correct a change if we are out of normal range of something

negative feedback loops

resists a change from a set point

maintains the body within its preferred range of conditions

steps to negative feedback loops

stimulus, sensor, control, effector, response

sensor

does not know whether something is good or bad, just senses the level

control (center)

is able to tell if the level is out of range

often the central nervous system

effector

where the response happens; the part of the body that does the response to reverse the initial change

positive feedback loops

more rare

intensifies/increases a change in the body

ex: childbirth, blood clotting, breastfeeding

steps to positive feedback loop

stimulus

intensified action

endpoint - tells the body to eventually stop

parts of atom

proton, neutron, electron

three types of chemical bonds

ionic

covalent

hydrogen

ionic bonds

between a metal and nonmetal ions

one atom steals the electron(s) of another

covalent bonds

ions share electrons

between two nonmetals

polar covalent

has regions of opposite charges (partial charges)

big example: water (O is more electronegative than H), the partial charge on H allows for hydrogen bonding

hydrogen bonds

relatively weak, but when there are many it can be strong

the partially positive hydrogen atom bonds to the partially negative oxygen atom of two or more water molecules

salt

an ionic compound (cation-anion) which is hydrophilic because they are all highly polar

therefore they dissolve easily in water

solubility rule

like dissolves like

polar likes polar; nonpolar likes nonpolar

what is the polarity of hydrophobic molecules

nonpolar, which is why it doesn’t dissolve in water

made of hydrocarbons

think oil and water