Chapter 6/7/8 - Cell Membranes Flashcards
Cell Theory
- All organisms are composed of 1 or more cells , and life process of metabolism and heredity occur within these cells
- Cells are the smallest living things and and are the basic unit of organization in all living organisms
- Cells arise only by division of pre existing cells
True or false
Life represents a continuous line of descendants from those early cells
True
What is the reason why cell are small ?
Diffusion into and out the cell
The small size of cells allow
Diffusion to occur easily
Lower energy expenditure
Lower waste
Surface are to volume ratio
Volume increases rapidly as a cell increases in size
1-10um in diameter
Prokaryotes
10-100um in diameter
Eukaryotes
How do we visualize cells
With use of technology (microscopes)
- cells are not visible to the naked eye (resolution)
What is the purpose of chemical stains
Chemical stains aid the resolution of cells, make them more visible through a microscope
What are the 4 major components of a cell?
- nucleoid or nucleus
- cytoplasm
- ribosomes (synthesize proteins)
- plasma membrane
Production of protein is achieved by
Ribosomes
How many subunits make up a ribosome
2
Large subunit
Small subunit
The area of a prokaryotic cell (simplest organism)
Nucleoid
Eukaryotes (complex organisms) are contained in the
Nucleus
The nucleus is surrounded by a double membrane called the
Nuclear envelope
What is cytoplasm?
What does it contain?
Semi fluid matrix that fills the cells interior
Contains sugars, amino acids, proteins, and organelles used to carry out daily activities.
Cytosol
The part of the cytoplasm that contains organic molecules and ions in solution
Organelle
Specialized part of a cell, small cytoplasmic organ
Separates the inside of the cell from the outside environment
plasma membrane
Plasma membrane is composed of
Phospholipids and contains membrane proteins
What is embedded in the plasma membrane
Proteins
Phospholipid molecule make up the
Plasma membrane
What is responsible for the cells ability to interact with the environment
Proteins of plasma membrane
Lacks membrane bound nucleus, internal membrane system, and membrane bound organelles
Prokaryotes
Prokaryotes are small simple cells surrounded by
Cell wall
True or false
Prokaryotes have no compartments
True
Prokaryotes lack
Membrane bound organelles
Lack cytoskeleton found in eukaryotes. But have elements of actin and tubulin to help maintain its structure
Prokaryotes have
Free floating ribosomes to synthesize proteins
Name two types of prokaryotes
Bacteria
Archaea
Bacterial cell wall is composed of
Peptidoglycan , a sugar polymer
Functions of bacterial cell wall
Protect the cell
Maintain its shape
Prevent excess uptake or loss of water
Archaea Cell Wall is composed of various chemical compounds such as
Proteins
Polysaccharides
Inorganic compounds
Archaea Cell Membrane
A fatty acid chain (saturated hydrocarbon) that is covalently attached at both ends to glycerol, creating a monolayer rather than a bilayer
Can archaea adapt to changing environmental temperatures?
No. Unable to alter the degree of saturation of hydrocarbons
The cellular machinery that replicates DNA and synthesized proteins in archaea is more closely related to
Eukaryotic systems than bacterial systems
Long, threadlike structures protruding from the surface of a cell that are used for locomotion(movement)
Flagella
Prokaryotic Flagella
Protein fibers that extend out from the cell wall.
(Rotary Motor)Movement powered by proton gradient
There may be one or more per cell, or none depending on species.
Eukaryotic Cells
Contains an endomembrane system that allows the inside to be compartmentalized —- this allows biochemical reactions to occur independently and simultaneously through organelles
Common organelles found in animal, fungi, and plant cells
Nucleus Nucleolus Ribosomes Cytoplasm Endoplasmic Reticulum(rough/smooth) Golgi Apparatus Lysosome Peroxisome Plasma Membrane Mitochondria Cytoskeleton (actin filaments, microtubules)
Largest organelle, spherical in shape, typically located in the center of a cell
Nucleus
The nucleus contains ______________
Which are packaged DNA, or gene coding for protein
Chromosomes
All eukaryotic cells are supported by an internal protein scaffold called
Cytoskeleton
DNA are packed to form_____________ which are further packed by proteins to form_______________
Chromatins
Chromosomes
Two phospholipid bilateral that surrounds the nucleus
Nuclear Envelope
Describe the nuclear envelope
One layer surrounds the nucleus
The outer phospholipid bilayer forms the endoplasmic reticulum, or cytoplasm interior Membrane system
The outer phospholipid bilayer of the nuclear envelope forms the
Endoplasmic reticulum
Network of intermediate filament fibers that covers the inner surface of the nuclear envelope , which give the nucleus its shape
Involved in the deconstruction and reconstruction of the nuclear envelope that accompanies cell division
Nucleus lamins
Found embedded between two phospholipid bilayers
Scattered over the surface of the nuclear envelope
Nuclear pores
Nuclear pores allow
- Ion and small molecule exchange or diffuse between nucleus and cytoplasm
- controlled transport of large proteins and RNA, RNA - protein complexes into and out of the nucleus
Nucleolus is found within
The nucleus
Houses ribosomal RNA genes, RNAs, and ribosomal proteins within itself during ribosome production
Nucleolus
Manufactures ribosomal RNA subunits (ribosomes) needed to synthesize protein
Nucleolus
Organelle within a cell that is important in synthesizing protein
Ribosome
Newly made protein is found in the
Cytoplasm
The large subunit and small subunit of ribosome is composed of a combination of RNA called
- rRNA, or ribosomal RNA
2. Proteins
Subunits of ribosome form only when
They are actively synthesizing proteins
Messenger RNA (mRNA)
Carries coding information from DNA
Transfer RNA (tRNA)
Carries amino acids
Ribosomes use the information in mRNA to direct the
Synthesis of protein
Ribosomes are found
Free in the cytoplasm
Associated with internal membranes
Embedded in the ER
Contains the message or protein sequence to be made
mRNA
Will read the mRNA and translate it into an amino acid chain
rRNA(ribosomes)
Will provide the amino acids to build the growing peptide chain
tRNA(ribosomes)
Factories that make proteins
Ribosomes
Cell interior contains an endomembrane system that
Divides the internal cell into compartments
What forms the largest endomembrane?
Endoplasmic reticulum
Exists as folded membranes, tubular networks, and other shapes
Endoplasmic reticulum
Phospholipid bilayer forms the
Endoplasmic reticulum
Cisternal Space/ lumen
Interior of ER
Two types of ER
Rough ER
Smooth ER