Module 1 Flashcards
What are the 2 types of electron microscopes? Which one produces 3D images?
Transmission Electron Microscope
Scanning Electron Microscope (produces 3D images)
What are 2 technologies used to study cells?
Which one allows the use of live specimens?
Light microscopes
Electron microscopes
Light microscopes allow the use of live specimens.
Define diffusion:
The movement of molecules from a region of high to low concentration.
How does a high or low pH affect an enzyme?
It causes the enzyme to denature.
What is the nucleus?
An organelle in the cell that contains DNA.
What is denaturation?
The unfolding or breaking down of a protein. This is caused by changes in temperature or pH.
What does the golgi apparatus do?
Receives proteins and lipids from the ER and sorts, modifies and packages them.
What is the difference between prokaryotic and eukaryotic cells?
Eukaryotic cells have membrane bound organelles while prokaryotic cells don’t.
What does an enzyme act upon?
A substrate
What are ribosomes responsible for?
They turn amino acids into protein through protein synthesis.
What does the mitochondria do?
Produces ATP (energy) through cellular respiration.
What are 2 disadvantages of light microscopes?
Less resolution and magnification
Specimens often need to be stained to be viewed.
What is passive and active transport?
Passive transport doesn’t require energy and moves with the concentration gradient.
Active transport requires energy and moves against the concentration gradient.
What are enzymes?
Biological catalysts that speed up reactions.
What do lysosomes do?
The are responsible for digestion and waste removal for the cell.
What is the cell membranes?
It separates the inside of the cell from the outside and controls what goes in and out of the cell.
What part of the phospholipid is hydrophilic and hydrophobic.
Head is hydrophilic
Tail is hydrophobic
What organelle carries out photosynthesis.
Chloroplast
Describe at least 2 disadvantages of electron microscopes.
- The specimen must be dead because it is placed in a vacuum before viewing (air would interfere with the electron flow)
- Only black and white images
- There is a complicated preparation process which may introduce artefacts into the image.
- Size and expense
What are channel proteins?
They allow direct passage through the cell membrane.
Define osmosis:
The movement of water from high to low concentration through a selectively permeable memerane.
What is facilitated diffusion?
When proteins in the cell membrane help transport larger molecules across the membrane.
What is the biological level of organisaion?
Atoms, molecules, organelles, cells, tissues, organs, organ systems, organisms
What do carrier proteins do?
Bind to molecules and change shape to transport the molecule through the cell membrane.
What is a solute?
The substance being dissolved.
What is the difference between integral and peripheral proteins.
Integral proteins go all the way through the membrane while peripheral proteins are only partly embedded in the membrane.
What is an active site?
Where the substrate binds to the enzyme.
What makes up the bilayer of the cell membrane?
Phospholipids
What is the endoplasmic reticulum (ER)?
The ER is a network of membranes that transport materials such as protein and lipids within the cell.
What does a vacuole do?
Stores food and waste
What are 2 advantages of electron microscopes?
- Higher magnification and resolution than light microscopy.
More detailed images of structures that are complex.
What does a rough ER have attached to it?
Ribosomes
