chapter 4 & 5 Flashcards
What do all living cells have?
A plasma membrane, Ribosomes, DNA &RNA, and Cytoplasm
What is the Cytoplasm? What does it do?
The Cytoplasm is the gel-like fluid in cells. It gives cells structure and is where all organelles float around.
What are the features of the Nucleus?
The Nucleus is where all the genetic information is stored, it is surrounded by a double membrane with pores, and connects to the endomembrane system.
What is the Endoplasmic Reticulum and what does it do?
the ER is a series of interconnected tubules. It modifies proteins and synthesizes lipids.
What does the Golgi Apparatus do?
It sorts, tags, packs, and distributes lipids and proteins.
What are the key characteristics of Ribosomes?
Ribosomes are found in all cells and they are responsible for protein synthesis. They typically appear as single dots or clusters of dots floating around in the cell’s cytoplasm.
Tell us about the Powerhouse of the Cell!!
Mitochondria! They produce the cell’s main energy-carrying molecule: Adenosine Triphosphate (ATP). They also have their own DNA and Ribosomes.
Who proposed the cell theory?
Botanist Matthias Schleiden and zoologist Theodor Schwann.
What did Rudolf Virchow do?
He made great contributions to the cell theory.
What does the cell theory state?
It says that all living things are composed of one or more cells, that cells are the smallest unit of life, and that new cells arise from pre-existing cells.
What are microscopes used for?
To study forms and parts of life
How many types of microscopes are there?
Two, light microscopes and scanning and electron microscopes.
What are light microscopes?
Microscopes that study both living and dead cells. They use light photons to focus the specimen.
What are scanning and electron microscopes?
Microscopes that have higher magnification and higher resolution. But sample preparation kills the specimen, meaning it can only study dead specimens. It uses electrons to focus the specimen.
What are ribosomes?
Particles that synthesize proteins.
What are the key characteristics of prokaryotes?
single-celled organisms that lack a true nucleus or other membrane-bound organelle. They sometimes have flagella, pili, or fimbriae.
What are the key characteristics of eukaryotic cells?
Can be single-celled or multicellular organisms, have a true nucleus, and are typically larger than prokaryotes.
What is the typical size of prokaryotes?
0.1-0.5 ym
What is the usual size of eukaryotes?
10-100 ym.
What is the purpose of prokaryotes’ smaller size?
Their smaller size helps ions and organic materials to enter and spread through them quickly.
What is the purpose of eukaryotes’ larger size?
Eukaryotes are larger because they have structural adaptations to help cellular transport.
What are the characteristics of eukaryotes?
Nucleus, mitochondria, a cytoskeleton, flagella and cilia, chromosomes, mating, and cell walls in some cells.
What is endosymbiosis?
The process where one cell gets engulfed by another and both get benefitted from each other.
Where can we find evidence for endosymbiotic origin?
In mitochondria and in plastids.
What is the function of the plasma membrane?
It separates the cell from the outer environment and controls the passage of organic molecules, ions, water, oxygen, and wastes into and out of the cell.
What is the nucleoid?
the location of DNA.
What is the function of the nucleus?
Houses DNA and directs synthesis of ribosomes and proteins.
What do mitochondria produce?
They produce ATP.
What do peroxisomes do?
Oxidize and break down fatty and amino acids, and detoxify poisons.
What is the function of vesicles and vacuoles?
Storage and transport, digestive function in plant cells.
What is the function of the centrosome?
They have an unspecified role in cell division in plant cells; they are the source of microtubules in animal cells.
What is the purpose of lysosomes?
They digest macromolecules and recycle worn out organelles.
What do chloroplasts do?
Photosynthesis!
flagella?
Cellular locomotion
What does cilia do?
Cellular locomotion, movement of particles along extracellular
surface of plasma membrane, and filtration.
One major component of the cytoplasm in both prokaryotes and eukaryotes is the gel-like cytosol. What is cytosol?
A water-based solution that contains ions, small molecules, and macromolecules.
Are ribosomes found in all cells?
Yes, but they are smaller in prokaryotic cells.
What about mitochondria supports endosymbiotic theory?
They have their own ribosomes and DNA.
Vesicles are membrane-bound sacs that function in storage and transport, what are their functions?
metabolism, transport, buoyancy control, and enzyme storage.
What are the three cytoskeletal fibers?
Microfilaments, intermediate filaments, and microtubules.
What are microfilaments?
The thinnest of the cytoskeletal fibers, they function in moving cellular components.
What are intermediate filaments?
they are of intermediate diameter and have structural functions.
what are microtubules?
they are the thickest of the cytoskeletal fibers, guide organelle movement, and are the structures that pull chromosomes to their poles during cell division.
What are flagella?
long, hair-like structures that extend from the plasma
membrane and are used to move an entire cell.
What are cili?
When cilia (singular = cilium) are present, however, they are many in number and extend along the entire surface of the plasma membrane.
