Topic 4 (Study Objectives) Flashcards
What are the three points of Cell Theory?
(1)The cell is the basic unit of life (2)All living things are made up of cells (3)New cells arise only from pre-existing cells
Why do cells need to stay small?
because they must have a large surface area to volume ratio to function properly.
Prokaryotic cell components
cell wall, ribosomes.
Eukaryotic cell components
nucleus, membrane-bound organelles, an endomembrane system.
How are prokaryotic cells different from eukaryotic cells?
prokaryotic cells do not have a nucleus or membrane bound organelles and are smaller than eukaryotic cells.
What parts make up the nucleus in a eukaryotic cell?
nuclear envelope, nuclear pores, nucleoplasm, cromatin, and nucleolus
What is the function of the nuclear envelope?
surrounds the nucleus.
What is the function of the nuclear pores?
they control the passage of ions, molecules, and RNA.
What is the the nucleoplasm?
The specialized liquid inside the nucleus similar to cytoplasm.
What is the function of the cromatin?
(DNA wrapped around proteins) help store hereditary information.
What is the function of the nucleolus?
contains RNA for ribosome synthesis
What is the basic process of protein synthesis?
DNA -> RNA -> Protein
What are the two processes involved in protein synthesis?
transcription and translation
What is transcription in protein synthesis?
it is the first part where the genetic instructions in DNA are transferred to mRNA. This happens in the nucleus of a cell, then the mRNA leaves the the nucleus and goes to the cytoplasm and eventually a ribosome.
What is translation in protein synthesis?
it is the second part where the RNA becomes a protein. The ribosomes decode information on mRNA and translates to a polypeptide chain (protein).
What is the function of rough ER?
it has ribosomes attached therefore it makes proteins. (is apart of protein synthesis).
What is the function of smooth ER?
it had no ribosomes, it produces carbs, lipids, and steroid hormones and detoxifies drugs, alcohol metabolism, and stores calcium. (not apart of protein synthesis).
What is the structure of the golgi apparatus?
it is a large organelle, made of a stack of flattened vesicles (membranes sacs).
What is the function of the golgi apparatus?
it is where the sorting tagging, packaging and distribution of lipids and proteins takes place after they have been through the rough ER.
What is the function of lysosomes?
it is basically the cell’s “garbage disposal”. They contain lytic enzymes (digestive enzymes) that dispose of unwanted material. They work best at a slightly acidic pH of 5.
What are the two function of peroxisomes?
(1) breaks down fatty acids and amino acids into hydrogen peroxide/ H2O2 (2) detoxifies poisons such as alcohol in the liver
What is the function of vacuoles?
Storage and transport. Encloses food, waste, water, sugars, and pigments.
What does the endomembrane system do?
works together to modify, package and transport lipids and proteins.
What makes up the endomembrane system?
the nuclear envelope, lysosomes, vesicles, ER, golgi apparatus, and the plasma membrane.
What is the structure of the mitochondria?
They have their own DNA and RNA and a double membranes (an inner and outer membranes). Inside are folds called cristae and the mitochondrial matrix.
What is the function of the mitochondria?
It is the cell’s “power house” produces ATP from carbohydrates like glucose.
What is the structure of chloroplasts?
Found in plants and algae; They have their own DNA and RNA. and a double membranes (an inner and outer membranes). Inside are fluid-filled membrane sacs called thylakoids. Each of the stacks of thylakoids are called granum.
What is the function of chloroplasts?
Produces energy. photosynthesis; they trap solar energy and convert it to carbohydrates like glucose and oxygen.
What similarities does the mitochondria and chloroplasts have?
The both are energy producing organelles, They have their own DNA and RNA. and a double membranes (an inner and outer membranes).
What is the structure of cytoskeleton?
made up of a network of three different protein fibres.
Where the three protein fibres in the cytoskeleton?
(1)Microfilaments (smallest, change cell shape) (2)Intermediate filaments (maintains cell shape) (3)Microtubules (largest, maintains cell shape, movement of organelles, cell mobility [cilia and flagella])
What is the function of cytoskeleton?
maintains cell shape
What are some example of how cell surface variation affects function?
(1)sperm cells have flagellum to move and fertilize an egg. (2)Animal cells have an extra cellular matrix for protection and support. (3)Plant cells have a cell wall that maintains cell shape
What is the intercellular junction in plant cells called?
plasmodesmata (for communication between cells)
What are the intercellular junctions in animal cells called?
(1)tight junctions (2)desmosomes (3)gap junctions
What are tight junctions?
a watertight seal between cells (for leak protection)
What are desmosomes?
strength, anchoring junctions
What are gap junctions?
for communication between cells or for transport
What do plant cells have that animal cells do not have?
plasmodesmata, cell wall, large central vacuole, chloroplasts and plastids.
What do animal cells have that plant cell do not have?
lysosomes and centrosomes.
