Lecture #3 - Cell Structure Flashcards
________ cells are the basic functional units of the body
animal
Name the principal parts of animal cells
- plasma membrane
- cytoplasm and organelles
- nucleus
What does a collection of organelles and cytosol give rise to? Define it
cytoplasm: semi-fluid material; the entire content within the cell membrane (contains organelles and cytosol)
What is the function of the mitochondria? By what process does it carry out its function?
- site of energy production (ATP)
- aerobic cellular respiration
Describe the mitrochondria structure
- double membrane: inner and outer membrane
- two spaces: intermembranous space (between the inner and outer membrane) and the matrix (central area, fluid)
- cristae: folding of the inner membrane; increases surface area for reactions
What is a cristae and where is it located?
inner membrane of mitochondria is folded into a cristae in order to increase surface area for reactions
Which organelle’s function is to make (synthesize) proteins?
ribosomes
Ribosomes are found ________ in the cytoplasm or associated with the __________ ___________ ________.
free
rough endoplasmic reticulum
____ types of ______ are involved in protein synthesis
3
RNA
What are the functions of the different types of RNA found in the ribosome?
- mRNA: takes genetic info to ribosome so protein can be made
- tRNA: carry amino acids
- rRNA: forms a part of the ribosome
Describe Ribosomes
- very small, made of 2 subunits
Name the 2 locations ribosomes are found in the cell?
- free in cytoplasm
- rough ER
What two membranes is the ER connected to?
- nuclear membrane
- plasma membrane
Compare the Rough ER from the Smooth ER
Rough ER
- ribosomes on the surface
- site of protein synthesis for the proteins transported to the golgi complex
Smooth Er
- no ribosomes on the surface
- several functions (depending on cell); lipid synthesis
Cavities within the __________ _________ are called ___________
golgi complex
cisternae
Name the 2 sides of the Golgi and how each side is different from the other
cis side: receives cell products (proteins) from the rough ER
trans side: vesicles exit and transported to cell surface for secretion of contents
Describe the Golgi Complex
- stacks of hollow, flattened sacks; cavities called cisternae
- The cis side of Golgi receives proteins from the rough ER
- Proteins chemically modified in cisternae
- Proteins packaged into vesicles
- Vesicles bud off from trans side
- transported to cell surface for secretion of contenets
T or F: Most animal cells are multinucleated
F
Most cells have ______ nucleus. There is an exception. ___________ _________ cells are ___________ and ___________ _________ ____________ cells have ______ __________.
one
Skeletal muscle, multinucleated
mature red blood, no nucleus
What is contained within the nucleus?
DNA and genes (+ nucleolus)
Define a gene
a segment of DNA strand that codes for a specific protein (genes make up proteins)
Define the nucleolus
darker region within the nucleus that is not surrounded by a membrane
contains DNA that codes for the production of rRNA
What contains DNA that codes for the production of rRNA?
nucleolus
What is the relationship between DNA and a gene
genes are segments of the DNA strand
Describe the process in which DNA becomes a chromosome
DNA wraps around histone protein -> several wrapped histones = nucleosome -> several nucleosomes = chromatin -> chromosome
What makes up the plasma membrane?
phospholipid barrier between the intracellular and extracellular environment (bilayer)
In the phospholipid bilayer located in the plasma membrane, many substance are _________ allowed to pass through protein channels
selectively
The nucleus is enclosed by the ___________ _______ that is made of ______ membranes.
What are these membranes?
nuclear envelope
2
- inner membrane
- outer membrane: continuous with rough ER
