Cell Theory & Basics
Who first discovered cells while looking at cork under a microscope?
Robert Hooke
The "control center" of the cell that contains DNA
Nucleus
The cell membrane is mostly made of this macromolecule.
What are phospholipids?
Define diffusion
movement of particles from high to low concentration
define homeostasis
maintaining stable internal conditions
This scientist observed scraping from his teeth under his own homemade microscope.
Anton Van Leeuwenhoek
What organelle converts sunlight into food in plant cells?
Chloroplast
This is what "selectively permeable" means
Allows some substances to pass through but not others
define osmosis
diffusion of water across a membrane
what is a negative feedback loop
a system that reverses a change to maintain stability
This is why cells are considered the basic unit of life.
They are the smallest structures that can carry out all the processes necessary for life.
Which organelle breaks down waste and old cell parts?
Lysosome
What is facilitated diffusion
movement through protein channels without energy
what happens to a cell in a hypertonic solution
water moves out, and the cell shrinks
Give an example of a positive feedback loop in the body
Childbirth contractions or blood clotting
What part of cell theory states how new cells form?
All cells come fro pre-existing cells
Explain how the rough ER and the golgi apparatus work together
Rough ER makes proteins -> golgi modifies and packages for tranpsort
What is the difference between active and passive transport
active needs energy passive doesn't
why does diffusion stop when equilibrium is reached
concentrations are equal
How does the cell membrane help maintain homeostasis?
It regulates what enters and exits the cell
List the 3 pieces of the cell theory
All living things are composed of cells
Cells are the basic unit of structure and function of life
All cells come from preexisting cells
A cell has many mitochondria. What might this tell you about the cell's function?
It requires a lot of energy.
This is why molecules like steroids can easily pass through the phospholipid bilayer, and molecules like glucose can't
Tails are hydrophobic and heads are hydrophilic
A plant wilts when placed in salt water. Why? (explain using osmosis)
Water leaves the cell, vacuoles shrink
Explain how cell signaling helps maintain homeostasis
cell send and receive messages to coordinate responses and balance conditions