Chapter 7: Inside the Cell Flashcards
What are the types of endocytosis?
Receptor-mediated, phagocytosis, and pinocytosis
What does the Golgi apparatus do?
Modifies, stores, and ships proteins. Adds molecular tags to proteins bound for secretion
Can bacteria be photosynthetic?
Yes, some species have membranes that fold in leading to photosynthesis.
What do prokaryotes and eukaryotes both have?
Ribosomes, plasma membrane, DNA, some organelles, some have cell walls
What do microfilaments (actin) do?
Muscle contraction and cell division (cleavage furrow formation)
What do different spots in the Golgi do to proteins?
They modify them as they pass
What does the endomembrane do?
Protein synthesis, transport, metabolism, synthesis of lipids, detoxification of poisons
What are peroxisomes?
Centers for redox reactions. Produce H2O2
What do bound ribosomes do? (bound to cytoplasm)
Make proteins which will be inserted into membranes or secreted
How does transport within the cell occur? (into and out of nucleus)
Nuclear transport
Why is it important lysosomes can only function in acidic conditions?
It ensures they can’t go everywhere and digest every organelle in the cell
Where does all protein synthesis start?
Free ribosomes
What are ribosomes made of?
Complexes of RNA and proteins
How does the Golgi take in and release proteins?
Proteins leave the RER and go into Golgi in vesicle and the membrane of the Golgi forms a vesicle around proteins for them to be secreted
What is special about a eukaryotes nucleus?
It is a true nucleus meaning it has a nuclear membrane that separates the DNA from the rest of the cell
How do drugs effect the SER?
Drugs cause the cell to make more SER and more SER means you will need more drugs to have an effect
What happens when lysosomes stop working?
Lipids build up and kill brain cells. A drug is needed to get the proper enzymes
How large are eukaryotic cells?
0.005 - 0.1 mm (5-100 micrometers)
What organelle is continuous with the plasma membrane?
Endoplasmic reticulum
Pathway for a synthesized protein that will be secreted by the cell
Free ribosome, bound ribosome, RER, Golgi, vesicle, cell membrane, out of cell
What does the rough ER do? (studded with ribosomes)
Proteins destined for secretions shipped to other organelles or embedded in membrane
Where does the growing polypeptide go when it is being secreted into the ER?
ER lumen
What do peroxisomes do?
Produce H2O2, contain catalase which breaks down H2O2, breakdown fatty acids, and detoxify alcohol and other toxic compounds
Plants, animals, fungi, protists are this
Eukaryotes
What do ribosomes do?
Carry out protein synthesis
What is contained in mitochondria?
Their own DNA and ribosomes
This helps maintain the shape of the nuclear membrane and helps its structure
Nuclear lamina
What do free ribosomes do? (free in cytoplasm)
Make proteins which will function in the cytosol (inside the cell)
What do chloroplasts do?
In plants, they are the site of photosynthesis. They take energy from the sun and turn it to glucose
What conditions do enzymes function best in?
Acidic conditions
How many cells are in the human body?
50-90 trillion, though it is difficult to be sure. They would circle the Earth 4.5 times if they were lined up
What is the nucleus surrounded by?
Nuclear membrane
How do cells stay organized inside?
Cytoskeleton
What does the nuclear membrane contain?
Nuclear pores that control entry and exit
What is the Golgi apparatus?
Stacks of membranous sacs that aren’t physically connected
How is volume calculated for a cell?
(4/3)pir^3
What are lysosomes?
Membranous sac of enzymes that digest macromolecules
How are molecules that need to get in the nucleus tagged?
Nuclear localization sequence (NLS)
What do signal peptides mark on proteins?
Proteins meant for endomembrane system or secretion
How does the cell distinguish what proteins are destined for the nucleus?
Specific amino acid sequences on the proteins
What is inside the nucleus?
DNA
Are ribosomes technically organelles and why?
No, because they aren’t surrounded by membrane
What diseases can come from mitochondria?
Diseases associated with mitochondrion DNA that usually deal with cellular respiration
What do prokaryotes have instead of a nucleus?
Nucleoid
How large are bacterial cells?
Less than 0.003 mm (3 micrometers)
What are the 3 types of fibers in the cytoskeleton?
Microtubules, microfilaments (actin), and intermediate filaments
What would happen if a cell got too large?
There wouldn’t be enough surface area (membrane) to let everything pass
What do intermediate filaments do?
Anchorage of nucleus and certain other organelles and formation of nuclear lamina (maintains nucleus shape so it doesn’t collapse)
What types of cells are a lot of ribosomes found in?
Cells with a high rate of protein synthesis like pancreatic cells (few million ribosomes)
What happens in mitochondria?
Cellular respiration (produces energy for the cell in the form of ATP)
What two organelles can replicate independently of the cell
Mitochondria and chloroplasts
What type of membrane do mitochondrion have?
Double membrane. Smooth outer membrane with inner membrane with lots of folds to increase surface area
What is phagocytosis?
Engulfing solid particles and breaking them down
What do microtubules (tubular polymers) do?
Cell motility (as in cilia or flagella) and chromosome movements in cell division (pull the chromosomes apart)
How are large molecules that are too big to come in through membrane proteins brought into the cell?
Endocytosis
What does the nucleolus do?
Synthesis of rRNA and assembly of ribosome subunits
How are molecules that need to get out of the nucleus tagged?
Nuclear export sequence (NES)
What do signal-recognition particles (SRP) do?
Escort free ribosomes to the ER membrane to become bound ribosomes
Eukaryotes are more complex than prokaryotes because…
The have more organelles and a wider variety of organelles
What is in the endomembrane system?
Plasma membrane, nuclear envelope, S and R ER, golgi apparatus, lysosomes, and vesicles/vacuoles
How are proteins secreted?
Exocytosis
What does dividing into a lot of smaller units do to the surface area?
It increases it
What is contained in chloroplasts?
Their own DNA and ribosomes as well as chlorophyll
Where are mitochondria mostly inherited from?
Mostly from mom but also from dad
How is surface area calculated for a cell?
SA = 4pir^2
What type of membrane do chloroplasts have?
Double membrane
What is autophagy?
Recycling the cell’s own organic material
What does the cytoskeleton do?
Structure (maintains the cell shape and anchors cellular components) and motility (cellular movement and cellular highways for proteins to walk organelles along)
Why are cells so small?
As we get more cells, we need more ways to take in and get rid of things, so more cells give access to taking in more and disposing of more
What does the smooth ER do? (lacks ribosomes)
Lipid processing and synthesis, storage of Ca ions and Ca pump to RER to create concentration gradient, detoxification of drugs and poisons
Bacteria and archaea are this
Prokaryotes
What does increased mitochondrial density lead to
Increased athletic performance
How are molecules inside the cell digested?
Lysosomes break them down to building blocks to they are recycled
What do many smaller cells provide over one larger cell?
A greater surface area to volume ratio
