Unit 2 Chapter 7.1 & 7.2 Inside the Cell Flashcards
All cells contain which of three structures?
cell wall, plasmids, and ribsomes
chromosomes, ribosomes, plasmas, and membrane
chromosomes, cell wall, and flagella
cell wall, flagella, and ribosomes
All cells are surronded by a plasma membrane, have one or more DNA-containing chromosomes, and need ribosomes to synthesize proteins.
What is the downside to eukaryotic cells being larger?
Ions and small molecules such as adenosine triphosphate (ATP), amino acids, and nucleoties cannot diffuse across a large volume quickly.
- if the ATP that supplies the chemical energy in cells is used up on one sideof the large cell, the ATP from the other side of the cell would take a long time to diffuse to that location.
All cells have 4 things:
- Plasma membrane (Cell membrane).
- Cytoplasm
- DNA
- Organelles
Because the eukaryotic cells re subdivided, the molecules required for specific chemical reactions are often locatedwithin a give compartment or organell.
Compartmentalization offeres two key advantegs, what are they?
- Incompatibile chemical reactions can be seperated
- Chemical reactions become more efficient.
How do chemical reactions become more effecient in compartimentalization.
- substrates required for a particular recation can be be localized and maintained at high concentrations within organelles
- if subtrates have been used up, in a particular part of the organelle, they can be replaced by substrates tht have only a short distance to diffuse
- groups of enzymes tht work together can be clustered on internal membranes instead of floating free in they cytoplasm.
What are four key differences between prokaryotic and eukaryotic cells?
- Eukaryotic chromosomes are found inside a membrane bound compartment called a nucleus
- eukaryotic cells are often much larger
- eukaryotic cells contain extensive amounts of internal membrane
- eukaryotic cells feature a particularly diverse and dynamic cytoskeleton
How does the location of DNA differ between bacteria/archea and eukaryotes?
Bacteria/archea:
in nucleoid (not membrane bound); plasmids also common
Eukaryotes:
Inside nucleus (membrane bound); plasmids extremely rare
How do internal membranes and organelles differ between bacteria/archaea and eukaryotes?
bateria/archaea:
extensive internal membranes only in photosynthetic species; limited types and numbers of organelles
eukaryotes:
large number of organelles; many types of organelles
How does the cytoskeleton differ between prokaryotic and eukaryotic cells?
Prokaryotic cells are limited in extent, relative to eukaryotes
eukaryotes are extensive–usually found throughout volume of cell
How does the size differ between eukaryotic and prokaryotice cells?
prokaryotic cells are smaller
Nucleous
In eukaryotic cells, the large organelle containing the chromosomes and surrounded by a double membrane.
- function as an information storage and processing center
- amonges the largest and most highly organized of all organells
- double membrane called the nuclear envelope
Nuclear enevelope
a double membrane that encloses the nucleous
- it’s studded with pore-like openings and it’s inside surface is linked to fibrous proteins that form a lattice-lice sheet called a nuclear lamina
Nuclear lamina
a lattice-like sheet of fibrous nuclear lamins, which are one type of intermediate filaments. Lines the inner membrane of the nuclear envelope, stiffening the envelope and helping organzie the chromosomes.
Do chromosomes float freely inside the nucleous?
No, each chromosome occupy a distinct area and is attached tht he nuclear lamina in atleast one distinct location.
Nucleolus
In eukaryotic cells, specialized structure in the nucleus where ribosomal RNA processing occurs and ribosomal subunits are assembled.
- where gene products are processed
- where the RNA molecules found in robosomes are manufactured and the large and small ribosomal subunits are assembled.
The nuclear envelope is continuous with an extensive series of membrane-bound sacs called the____________ (litrally, “inside-formed-network”).
endoplasmic reticulum
rough endoplasmic reticulum (rough ER)
The portion of the endoplasmic reticulum that is dotted with ribosomes. Involved in synthesis of plasma membrane proteins, secreted proteins, and the proteins localized to the ER, Golgi apparatus, and lysosomes.
- ribosomes associted with the rought ER synthesize proteins that will be inserted intothe plasma membrane, secreted to the cell exterior, or shipped to an organelle.
- as they are being manufactured by ribosomes, these proteins move to the interiro of the sac-like component of the ER
lumen
the inerior space of any hollow structure (e.g., the rought ER) or organ (e.g., sthe stomach)
- in the lumen of the rough ER, newly manufactured proteins undergo folding and other types of processing
What are the functions of the proteins that are manufactured/produced in the rough ER?
- some carry messages to other cells
- some act as a membrane transport proteins or pumps
- some are enzymes
the common them is that the rough ER prouducts are packaged into vesicles and transported to various distant destinations, often to the surface of the cell or beyond
smooth endoplasmic reticulum (smooth ER)
the portion of the endoplasmic reticulum tht does not have ribosomes attached to it. Involved in the synthesis and secretion of lipids.
What part of the eukaryotic cell contains enzymes that catalyze reactions involving lipids?
smooth ER
What are some of the functions of the smooth ER?
- depending on the type of cell, these enzymes may synthesisize lipids needed by the organism or break down lipids that are poisonous
- it’s a manufacturing site for phospholipids used in plasma membranes
- a reservoir ofr calcium ions (Ca2+) that act as a signal triggering a whide array of activities inside the cell
Fill in the blank regarding the endoplasmic reticulum.
____________ ER has ribosomes and functions primarily as a protein-manufacturing center; _______________ ER lacks ribosomes and functions primarily as a lipid-processing center.
Rough ER; Smooth ER
The __________________ is a site of protein processing, sorting and shipping. The _______________ apparatus is a collection of flattened vesicles called cisternae.
Golgi Apparatus