Cells Flashcards
What is a cell?
Smallest unit of life, made of organelles (made from molecules)
What are the 2 basis of cell theory?
- Cells are the basic structural and physiological units of all living organisms
- Every cell originates from another existing cell like it
T/F: cells cannot exceed the volume that can be nourished by materials passing through the surface membrane.
True
How do cells maintain homeostasis?
Uptake gasses, release waste products, uptake nutrients
What do all cells have in common? (4)
- Discrete units surrounded by a membrane
- Internal mass of cytoplasm (cytosol & ribosomes)
- Contain DNA
- Require energy
What are the two componants of the plasma membrane?
Phospholipids, proteins
Which is bigger? A eukaryotic or prokaryotic cell?
Eukaryotic
What are the plasma membrane functions? (5)
- Maintain structural integrity
- Selective permeability
- Recognition between cells
- Communication between cells
- Stick cells together to form tissues and organs
What are the componants of the nucleus? (3)
- Double membrane
- Nuclear pores
- Nuclear lamina
What are the functions of the nucleus?
- Has chromatin (site of DNA replication
- Site of transcription
- Ribosomes produced
What is the ER? (3)
- 1/2 total membrane in cell
- Continuous with nuclear envelope
- Network of membrane tubules and sacs (cisternae)
T/F: The ER makes up of 1/2 the total membrane in a prokarotic cell.
False, eukaryotic
What does the RER do?
The ribosomes make proteins and membrane.
Transports, secretes, and modifies those proteins
What are the two sites of protein synthesis?
- In the cytosol
- On the outside of the ER
T/F: Free ribosomes make proteins that stay inside the cell and ER ribosomes make proteins that are sent out of the cell
True
What are the characteristics of the SER?
No ribosomes, variety of metabolic processes
What are some of the metabolic processes of the SER?
- Synthesizes lipids, phospholipids, and steroids
- Metabolizes carbs
- Stores calcium
- Detoxifies poison
T/F: The SERs function will change depending on where the cell is located in the body.
True
What do the golgi apparatus do? (3)
- Recieve proteins
- Further modify proteins
- Concentrate, package, sort proteins
What do the GA do in plants?
Make carbs for cell walls
What are some characteristics of the GA (4)
- Cis and trans side
- Structurally similar to ER
- 5-20 cisternae
- Internal spaces not continuous like ER
What are vesicles?
Hollow spherical organelles for transporting proteins
What can all the membranes break off and merge with each other?
All are phospholipids
What is a vacuole for?
Storage
What are the types of vacuoles?
Food vacuoles, contractile vacuoles, central vacuoles.
What are some vacuole examples?
Plant tonoplast, paramecium contractile vacuole
T/F: vacuoles can give structure to plants?
True
What is the pH of lysosomes and why?
- If it was closer to 7 it would break down our body.
Where do primary lysosomes come from?
From the golgi complex
Where to the secondary lysosomes come from?
The primary lysosome and a vesicle fusing
How many enzymes do lysosomes have
40+
What are the functions of the mitochondria?
Makes ATP
Cellular respiration
Convert food energy to ATP
What are the infoldings of the mitochondria called?
Cristae
What are the two mitochondria membranes?
outer and inner
What is the interior to innner membrane called in the mitochondria?
matrix
What are chloroplasts?
member of familty called plastids, pigment found in cells
what do chloroplasts do?
Make sugar instead of ATP
T/F: mitochondria are found in plants too
true
T/F: chlorophyll is the only pigment used for photosynthesis
false
What is the interior to inner membrane called in the chloroplast?
Stroma
What are thylakoids?
membrane of flattened sacks in the stroma
What is each stack of a thylakoid called?
A granum
What is the common function of mitochondria and chloroplasts?
Energy conversion
What is endosymbiont theory
That mitochondria were originally bacteria until the cell absorbded them and found them useful.
What are the 5 pieces of evidence for the endosymbiont theory?
- inner membranes with enzymes and transport system homologus to prokaryote.
- Replicate by a splitting process similar to prokaryotic binary fission
- Each organnell has a single, circular DNA molecule not associated with histone
- Contiain molecules to make proteins from their DNA
- ribosomes of mitochondria and plastids are similar to prokaryotic ribosomes
What are peroxisomes?
Organelle that transfers hydrogens from substrate to oxygen (converts hydrogen peroxide to water and O2 )
T/F: peroxisomes do not self replicate
false
