chapter 3: cells
What three things does every cell have? What cell is the exception to this “rule”?
a plasma membrane (or cell membrane), cytoplasm, and DNA (genetic material). Except a mature red blood cell, lack a nucleus (and thus no nuclear DNA)
the “special characteristics” of neurons.
Excitability (Irritability), Conductivity, Secretion, Extreme Longevity + Amitosis
When is an atom considered “stable” or “nonreactive”?
2 or 8 electrons in its outermost shell (or has gained/lost electrons to get there, like ions
what are recruited first small muscle fibers or big muscle fiber
small
What are the four main elements that make up the human body?
Oxygen (O)
Carbon (C)
Hydrogen (H)
Nitrogen (N)
What is diffusion? What causes diffusion to speed up? Slow down?
Diffusion is the passive movement of particles (such as molecules or ions) from an area of higher concentration to an area of lower concentration, driven by random molecular motion and a concentration gradient. Increased heat gives particles more kinetic energy, so they move and collide faster.
What is the resting membrane potential of a neuron? Threshold potential of a neuron
the major functions of connective tissue.
“Support, Bind, Protect, Transport, Store.”
What is a load?
Load = the weight or resistance the muscle is trying to move.
So “load” is literally just “how heavy the thing is that the muscle is working against.” That’s it! 💪🏋️♂️
what are weight, compound and molecules
weight: Usually means mass – how much stuff is in something. Measured in grams or kilograms.
compound: A molecule that is made of two or more different kinds of atoms
molecules: Two or more atoms stuck together. Can be the same kind or different kinds.
Be able to distinguish between the three types of tonic solutions.
Tonicity Type: Solute Concentration (vs. Cell Interior)
Hypotonic Lower (dilute solution)
Isotonic Equal
Hypertonic Higher (concentrated solution)
Key Terms/Observations
"Hypo = swell" (animal)
Equilibrium; no change in shape
"Hyper = shrink
the basic structure of a neuron – what are the dendrites, axons, cell body, etc.
Dendrites (receive) → Cell body → Axon (send) → Axon terminals (talk with chemicals)
Know the two types of proteins found in the plasma membrane and what their major functions are.
put the steps of skeletal muscle contraction in order
“Nerve → ACh → Receptor → AP → T-tubule → Calcium → Troponin → Slide!”
What is a solute? Solvent? What is the universal solvent?
Solute: The stuff that gets dissolved (usually the smaller amount) ex. Sugar, salt, Kool-Aid powder, coffee grounds
solvent: The stuff that does the dissolving (usually the bigger amount) ex. Water in your drink, water in the ocean
The Universal Solvent = WATER
the difference between primary and secondary active transport and when they are used.
Secondary is more energy-efficient as it reuses the gradient created by primary transport, amplifying the effect of ATP used in primary pumps. Both are essential for homeostasis, especially in animal cells.
How do polar and non-polar molecules differ? What is electronegativity?
Polar = “has poles” like a magnet → water dissolves salt and sugar (likes other charged things)
the format of a chemical reaction – reactants, products, arrows, reversibility.
Reactants
The “stuff you start with” (left side) A + B
Arrow → Means “reacts to make” or “yields” A + B →
Products The “new stuff you end up with” (right side) A + B → C + D
Reversible arrow ⇌ Reaction can go both ways (forward & backward) A + B ⇌ C + D
the difference between twitch, wave summation, and tetanus.
What is an ionic bond? what is covalent? give an ex of each
the four types of vesicular transport and be able to distinguish between them if I gave you an example.
1. Endocytosis 2. Exocytosis 3.Transcytosis 4. Inside-the-cell transport
what type of membrane channel proteins we have and what type of stimulus would open them.
the cells of the epidermis and what their functions are.
Keratinocytes “Keratin = tough skin makers”
Melanocytes Make melanin (brown pigment) → give you skin color and block UV rays. One melanocyte protects ~40 keratinocytes.
Langerhans cells Immune cells – grab germs/invaders and show them to your immune system.
Merkel cells “Merkel = touch sensors”
the 3 types of skeletal muscle fibers – REDSOX, FOG, and FG, and be able to distinguish between them given a description.
“Red Sox jog all day (slow + red + never tired) FOG can go fast AND long (pink middle guy) FG is the white-meat chicken sprint king (fast but gasses out quick)”
In ionic bonding, what becomes oxidized? what becomes reduced
“The metal gets oxidized, the non-metal gets reduced.”