Book : Ch. 4 Flashcards
What is a cell?
A cell is the smallest unit that shows the properties of life
What four generalizations make up cell theory?
- Every living organism consists of one or more cells
- The cell is the structural and functional unit of all organisms. A cell is the smallest unit of life, individually alive even as part of a multicelled organism
- All living cells come from a division of other pre-existing cells
- Cells contain hereditary material which they pass on to their offspring during division
What is a eukaryotic cell?
A cell containing a nucleus
What is a prokaryotic cell?
A cell without a nucleus
What is a plasma membrane?
Cells outer membrane
What is a nucleus?
Double membraned sac holding a eukaryotic cells DNA
In prokaryotic cells where is the DNA found?
In a region of cytoplasm called the nucleoid region
What is a cytoplasm?
A semi fluid mixture of water, sugars, ions, and proteins between the plasma membrane and the region of DNA
What are ribosomes?
Structures on which proteins are built and suspended in cytoplasm
What is surface to volume ratio?
A physical relationship
What is a lipid bilayer?
The structural foundation of all cell membranes
What is a cell wall?
A rigid wall surrounding the plasma membrane of nearly all prokaryotes.
What is flagella?
Slender cellular structures used for motion
What is a pili?
Protein filaments that helps cells cling to or move across surfaces
What are biofilms?
Communial living arrangements in which single celled organisms live in shared mass of slime
What does the endoplasmic reticulum do?
Routes and modifies new polypeptide chains and synthesizes lipids
What does a Golgi body do?
Modifies new polypeptide chains and sorts and ships proteins and lipids
What do vesicles do?
Transport, store and digest substances in a cell
What do mitochondrion do?
Make ATP by sugar breakdown
What do chloroplast do?
Make sugars in plants and some Protists
What does a lysosome do?
Intracellular digestion
What does peroxisome do?
Inactivates toxins
What does a vacuole do?
Stores things
What is an organelle?
Structure that carries out a specialized function in a cell
What does a ribosome do?
Assembles polypeptide chains
What does a centriole do?
Is an anchor for cytoskeleton
What is a nuclear envelope?
The membrane of a nucleus
What is a nucleoplasm?
A viscous fluid similar to cytoplasm
What is a nucleolus?
A dense irregularly shaped region where subunits of ribosomes are assembled from proteins and RNA
What is chromatin?
Name for all of the DNA together with its associate proteins in the nucleus
What is a chromosome?
Each molecule of DNA together with it’s many attached proteins
What is the endomembrane system?
Series of interacting organelles between the nucleus and the plasma membrane
What is endoplasmic reticulum ?
Extension of the nuclear envelope
What are peroxisomes?
Containing enzymes that digest fatty acids and amino acids
What are vacuoles?
They isolate and dispose of waste, debris or toxic materials
What is a Golgi body
Attach phosphate groups or sugars and cleave certain polypeptide chains
What are lysosomes?
Vesicles that contain powerful digestive enzymes
What is a mitochondrion?
Type of organelle that specializes in making ATP
What are plastids ?
Membrane enclosed organelles that function in photosynthesis or storage in plants and algal cells
What are chloroplasts?
Organelles that are specialiZed for photosynthesis
What is a central vacuole?
An area where amino acids, sugars, ions, wastes, and toxins accumulate
What is a primary wall?
Plasma membrane cemented together by pectin and is then covered in cellulose
What is a secondary wall?
The secretion of material onto the primary walls inner surface forms the secondary wall
What is lignin?
A complex polymer of alcohols that makes up as much as 25% of the secondary wall of cells in older stems and roots
What is an extra cellular matrix?
Non living complex mixture of fiberous proteins and polysaccharides is secreted by cells and varies with the type of tissue.
What are cell junctions?
Structures that connect cells to other cells and to the environment
What are microtubules?
Long, hollow cylinders that consist of subunits of the protein tubulin
What are microfilaments?
Fibers that consist primarily of subunits of the globular protein actin
What is a cell cortex?
A reinforcing mesh under the plasma membrane
What are intermediate filaments ?
Stable parts of a cells cytoskeleton that strengthen and maintain cell and tissue structures
What are motor proteins?
Accessory proteins that move cell parts in a sustained direction when they are repeatedly energized by ATP
What are eukaryotic flagella and cilia?
Whiplike structures that propel cells through fluid
What is a centriole?
Barrel shaped organelle which remains below the finished area as a basal body
What are psuedopods?
False feet
