Chapter 3 Flashcards
What is the cell membrane primarily composed of?
Phospholipid bilayer (back-to-back phospholipids)
What contributes to the fluidity of membrane?
Cholesterol
What is the difference between saturated and unsaturated fatty acids?
Unsaturated fatty acids result in kinks in the hydrophobic tails
Hydrophobic definiton
repels water
Hydrophilic definition
attracts/likes water
What is an amphipatic molecule?
Molecule that ocntains both a hydrophillic and hydrophobic region
T/F - Phos. bilayer is very rigid and hard
NO. Phos. bilayer is very fluid
What parts of the phospholipid bilayer touch the cytosol and ECF?
The hydrophobic heads
Which part of Phos. bilayer is hydrophobic and hydrophilic?
Head - Hydrophilic (non-polar)
Tail - Hydrophobic
What is the intracellular fluid (ICF)
Fluid interior of the cell
What is the extracellular fluid (ECF)
A watery medium environment outside of the enclosure of the cell membrane
What is interstitial fluid (IF)
extracellular fluid not contained within blood vessels
What is a glycoprotein?
Protein with carbohydrate attached
What is a glycolipid?
Lipid with a carbohydrate attached
What is an integral protein?
Protein within/embedded in the membrane
What is a channel protein?
Integral protein that allows particular materials to enter/exit cell
What do recognition proteins do?
Mark a cell’s identity so others can recognize it
What is a ligand?
specific molecule that binds to and activates a receptor
What is glycocalyx?
Fuzzy appearing sugar coating around the cell; formed from glycoproteins and other carbohydrates attached to the cell membrane
What is glycocalyx important?
It gives each of the individual’s trillions of cells the “identity” of belonging in the person’s body. This identity is the primary way that a person’s immune defence cells “know” not to attack the person’s own body cells, but it also is the reason organs donated by another person might be rejected.
What are peripheral proteins?
Proteins bound on the inner/outer surface of the lipid bilayer
What regulates the concentration of substances?
Cell membrane
What is Passive Transport?
transport of materials without use of cell energy
What is active transport?
transport of materials using ATP
What is selective permeability?
A cell’s ability to allow only substances meeting certain criteria to pass through it unaided
What is the criteria to pass through the cell membrane? (What must the substance entering be?)
relatively small, nonpolar materials
What is a concentration gradient?
The difference in concentration of a substance across a space. Molecules/ions will spread/diffuse from where they are more concentrated to where they are less concentrated until they are equally distributed in that space.
what is diffusion?
The movement of particles from an area of higher concentration to an area of lower concentration
T/F The higher the temperature, the quicker the diffusion
TRUE
What are the components of the Cell Theory? (4 of them)
- Cells are the building blocks of all plants and animals
- All cells come from the division of preexisting cells
- Cells are the smallest units that perform all vital physiological functions
- Each cell maintains homeostasis at the cellular level
What are sex cells, and what are they sometimes called?
Sometimes called “germ” cells, these are reproductive cells
What are male sex cells?
Sperm
What are female sex cells?
Oocyte (a cell that develops into an egg)
What are somatic cells?
All body cells other than sex cells
Which cells have a nucleus?
Eukaryotic
What is cytoplasm?
Liquid outside nucleus and inside cell membrane
What separates cytoplasm from the ECF?
Cell membrane
What comprises the cytoplasm?
Cytosol and organelles
What are the four functions of the plasma/cellular membrane? (SEE NOTES FOR COMPLETE ANSWER)
- Physical isolation
- Regulation of exchange with the environment
- Sensitivity to the environment
- Structural support
What is an organelle?
A “little organ”; One of several different types of membrane-enclosed bodies in the cell
Organelles + Cytosol = ???
Cytoplasm
What are the four letters of DNA and which matches up with which?
AT and CG (Adenine and thymine & Cytosine and guanine)
What is facilitated diffusion?
The diffusion process used for those substances that cannot cross the lipid bilayer due to their size, charge, and/or polarity. These substances are restricted to special protein channels and specialized transport mechanisms in the membrane
What is a nuclear pore?
A tiny passageway for the passage of proteins (used in facilitated diffusion)
What is osmosis?
The diffusion of water through a semipermeable membrane
What are isotonic solutions?
Two solutes that have the same concentration of solutes
What is a hypertonic solution?
A solution that has a higher concentration of solutes than another solution
What happens to hypertonic cells when water leaves via osmosis?
The cell shrivels
What is a hypotonic solution?
A solution that has a lower concentration of solutes than another solution
What can happen to cells in a hypotonic solution?
They can swell and burst
What does the sodium-potassium pump do? Where is it located?
Transports sodium out of a cell while moving potassium into the cell. Located in the membrane of many types of cells
What is the electrical gradient?
The difference in electrical charge aross a space
What is a symporter?
Secondary active transporters that move two substances in the same direction
What are antiporters?
Secondary active transport systems that transport substances in opposite directions
What is endocytosis?
Process od a cell ingesting material by enveloping it in a portion of its cell membrane.
What is phagocytosis?
The endocytosis of large particles.
What is pinocytosis?
brings fluid containing dissolved substances into a cell through membrane vesicles
How do immune cells engage in phagocytosis?
Many immune cells will patrol the body tissue for unwanted matter, such as invading bacterial cells, phagocytize them, and digest them
Receptor-mediated endocytosis
Endocytosis of only certain substances
Exocytosis
Cell exporting material using vesicular transport
What is cytosol?
Clear, semi-fluid medium of the cytoplasm, made up mostly of water
T/F The nucleus is an organelle?
True
What is oxidative stress?
- Damage to cellular components caused by reactive oxygen species
- Can remove electrons from other molecules, making them oxidized and reactive, and they can now do that to others
What are reactive oxygen species (ROS)
- Such a peroxides
- Highly reactive products of many normal cell processes (called free radicals)
What are some examples of ROS?
Superoxide (O2-), Hydroxyl radical OH, H2O2
Why are free radicals reactive?
Free radicals are reactive because they contain free unpaired electrons, they can easily oxidize other molecules causing cell damage/death
What is the cytoskeleton?
Framework of the cell
What are microvilli?
Structures on surface of cell that increase surface area
What are centrioles? What do they do?
- Direct mvt. of chromosomes during cell division
- Organize the cytoskeleton
- Cytoplasm surrounding the centrioles is the centrosome
What are cilia?
Beats rhythmically to move fluids across cell surface
What do proteasomes do?
Remove and breakdown damaged or abnormal proteins
Require targeted proteins to be tagged
What are lysosomes?
- “Slapchop”
- Filled with digestive enzymes
- Responsible for autolysis of injured cells
What are peroxisomes?
Carry enzymes that neutralize toxins
What is the membrane flow and where does it begin?
- Continuous mvt. of membrane
- Starts in ER, Vesicles, Gogli Ap, and then Cell Membrane
