Cell organelles and structures Flashcards
Explain the importance of surface area to volume of a cell.
The larger the surface area of a cell, the more volume it has, and the more difficult it is to get nutrients in and waste out. Smaller surface are to volume is ideal.
How do cells maintain surface area to volume?
They can split; add microvili; or fold; they can also elongate.
All cells share what four common components?
Plasma membrane; cytoplasm and cytosol; DNA; ribosomes
List five parts of the nucleus
nucleolus; chromatin; nucleoplasm; nuclear pore (complex); nuclear lamina
What is the nucleolus?
Nucleus of the nucleus; contains the condensed chromatin region where ribosomal RNA occurs.
What is chromatin?
unwound protein-chromosome complexes (where our DNA is)
What is nuceloplasm?
entire region within nuclear envelope and filled with semi-solid fluid.
What is a nucelar pore?
On the nucelus; allows substances in and out.
What is the nuculear lamina?
line nuclear side of inner membrane composed of intermediate filaments, proteins, and maintains shape of nucleus.
What is a ribosome?
Organelle in every cell; Protein factory. Made from rRNA.
What is the mitochondira?
Organelle in most cells; site of cellular respirtation; makes ATP
What are chloroplasts?
In plant cells; site of photosynthesis.
What are peroxisomes?
Organelle in some cells; contains hydrogen peroxide; breaks down fatty acids and amino acids; detoxifies many poisons. Found a lot in livers and kidneys.
What is a centrosome?
Microtubule organizing centers and centrioles complex. Only in animal cells.
What are cell walls?
In plants only; rigid protective structure external to plasma membrane. Made from cellulose.
What is a central vacuole?
Occupies most area of plant cell; regulates water concentration under changing environmental conditions; contributes to cell expansion.
What is cytoplasm?
the cells entire region between the plasma membrane and nuclear envelope; in plants and animal cells.
What is the nucelar envelope made of?
Double phosolipid bilayer with embedded proteins.
Describe a chloroplast.
Has inner and outermembrane. Inside are thykaloids.
What is the endoplasmic reticulum?
An organelle of a bunch of tubes and stacks connected to the nuclear envelope. Looks like nest. In the endomembrane system. Produces proteins for the rest of the cell in it’s ribosomes and packages them in the smooth portion.
What is the smooth endoplasmic reticulum?
Synthesizes carbs, lipids, steroids, hormones. DEHYDRATION because it is MAKING STUFF. Detoxifies medications/poisons. Proteins go through it and get ready for secretion.
What is the rough endoplasmic reticulum?
Covered in ribosomes; MODIFIES PROTEINS. Makes phospholipids for cellular membranes.
What are lysosomes and where are they found?
Break off from the golgi apparatus; through hydrolysis, they break down stuff; very acidic; uses enzymes to digest unwanted macromolecules. GARBAGE DISPOSAL OF THE CELL.
What are vesicles and vacuoles?
They move molecules around the cell; break off from the ER and the golgi and plasma membrane.
