Life at the Cellular Level Flashcards
Why are cells so small
Increased surface area to volume ratio
What are stem cells
Cells that can differentiate into many cell types (multipotent) or all cell types (pluripotent)
What are the 4 types of tissue
Epithelial
Connective
Muscular
Nervous
Properties of passive diffusion
Concentration gradient needed
Lipid soluble molecules pass freely (non polar)
Properties of facilitated diffusion
Concentration gradient needed
Requires carrier molecules
Which way do exocytosis and endocytosis transport across cell membrane
Exocytosis, out the cell, export
Endocytosis, into the cell
Properties of tight junctions
Create a physical barrier to diffusion across layers of cells
Dependent on calcium
Properties of adhesive junctions
Adherents junctions link actin filaments in two different cells
Desmosomes link keratin filaments in two different cells
Properties of gap junctions
Channels linking two cell cytoplasm together
Properties of mitochondria
Outer membrane contains pores Inner membrane is cristae Matrix contains binding sites for calcium and also most of the enzymes for oxidation of food molecules Their own circular DNA Synthesise most of their own proteins Self replicate
What do the Endoplasmic Reticulum and Golgi Apparatus do
Protein modifications and transport coordination
What are the uses of lysosomes
Used to separate enzymes from the rest of the cell
Used in autophagy or digestion of engulfed particles
Purpose of cytoskeleton
Supports and maintains cell shape Holds organelles in position Moves organelles Involved in cytoplasmic streaming Interacts with extracellular structures to hold cell in place
What is cilia
Short, numerous, move with stiff power stroke and flexible recovery stroke
What are flagella
Long, usually one or two present, movement is snakelike
