Cell Basics (Lecture 13) Flashcards
What does it take to make a cell?
- INFORMATION
(Dynamic)
What do all cells possess? What is its purpose?
All cells possess DNA, the hereditary material of genes, and RNA, that provide the information required to build the primary machinery of the cell.
What do red blood cells lack?
- Red Blood Cells lack nuclei, do not contain DNA, and cannot synthesize RNA - consequently, they do not divide and have limited repair capabilities.
- This feature of RBCs evolved to maximize hemoglobin carrying capacity.
When did LIFE start?
CHEMISTRY
What is The Miller-Urey Experiment?
The Miller-Urey Experiment (1952)
A chemical experiment that simulated the conditions thought to exist on the early Earth and to test the chemical origin of life under those conditions.
CHEMISTRY
What is the Oparin/Haldane hypothesis?
Conditions on the primitive Earth favored chemical reactions that synthesized more complex organic compounds from simpler inorganic precursors.
What does it take to make a cell? (3 things)
- Information (dynamic)
- Chemistry (matter and energy)
- Compartments
COMPARTMENTS
What is it usually defined as?
Give 3 examples of cellular compartments
Usually defined by a lipid membrane layer
Examples of cellular compartments:
- cell nucleus
- mitochondria
- chloroplasts
COMPARTMENTS
What are the two fundamental roles of compartments?
Fundamental Roles of Compartments:
- Establish physical boundaries that enable the cell to carry out different metabolic activities.
- Generate a micro-environment to spatially and temporally regulate biological processes.
*selective permeability*
HOMEOSTASIS
What is the cell theory?
- The cell is the structural unit of life (Schleiden & Schwann (1839))
- All organisms are composed of 1 or more cell types (Schleiden & Schwann (1839))
- Cells can arise only by the division of a pre-existing cell (1855)
What is the cell?
The cell is the fundamental unit of life
What are the 9 basic properties of cells?
- Highly complex and organized
- Activity controlled by a genetic program
- Can reproduce - make copies of themselves
- Assimilate and utilize energy
- Carry out many chemical Reactions - Enzymes
- Engage in mechanical activities
- Respond to stimuli
- Capable of self-regulation
- They evolve
Prokaryotic Cell vs Eukaryotic Cell
What is the difference?
The difference between prokaryotes and eukaryotes is an important distinction
among groups of organisms.
What are prokaryotes?
Prokaryotes were the only form of life on Earth for millions of years until more
complex eukaryotic cells came into being through the process of evolution.
Typical features of a bacterial cell
- pilus
- capsule
- cell wall
- plasma membrane
- nucleoid (DNA)
- cytoplasm
- ribosomes
- flagellum
Prokaryotic Cell vs Eukaryotic Cell
- Nucleus
- Plasma Membrane
- Nucleoid
Left cell: Prokaryotic cell
Right cell: Eukaryotic cell
Typical features of an animal cell
The function of the nucleus?
The nucleus is the storehouse for the cells genetic information and the site for RNA synthesis
Typical features of an animal cell
The function of the mitochrondria?
Mitochondria produce most of the ATP that serves as the energy currency of the cell
Typical features of an animal cell
The function of the plasma membrane?
The plasma membrane is composed of phospholipids and proteins and regulates the passage of materials into and out of the cell
Typical features of an animal cell
The function of the cytoskeleton?
The cytoskeleton is the network of protein filaments and other associated proteins that provide the cell with an internal structural framework
Typical features of an animal cell
The function of the endoplasmic reticulum?
The endoplasmic reticulum is involved in both protein and lipid synthesis
Typical features of an animal cell
The function of the Golgi apparatus?
The Golgi apparatus modifies and sorts proteins and lipids as they move to their final destinations in or out of the cell
Typical features of an animal cell
The function of the peroxisomes?
Peroxisomes break down specific organic molecules, such as fatty acids, and synthesize other organic molecules, such as cholesterol and some types of phospholipids.
Typical features of the plant cell
The function of the plant cell wall?
The plant cell wall is a rigid barrier composed of polysaccharides
Typical features of the plant cell
The function of the chloroplasts?
Chloroplasts enable plant cells to harness the energy of sunlight to synthesize sugars
Typical features of the plant cell
The function of the plasmodesmata?
Plasmodesmata connect neighboring plant cells
Typical features of the plant cell
The function of the vacuoles?
Vacuoles are organelles that contribute to the structural rigidity of plants by maintaining turgor pressure against cell walls
Animal vs. Plant
What are numbers 1, 2, 3, 4, 5, and their functions?
- Plasma Membrane controls the movement of molecules in and out of the cell and functions in cell-cell signaling and cell adhesion (Both)
- Mitochondria which are surrounded by a double membrane, generate ATP by oxidation of glucose and fatty acids (Both)
- Lysosomes, which have an acidic lumen, degrade material internalized by the cell and worn-out cellular membranes and organelles (Animal)
- Nuclear envelope, a double membrane, encloses the contents of the nucleus; the outer nuclear membrane is continuous with the rough ER (Both)
- Nucleolus is a nuclear subcompartment where most of the cell’s rRNA is synthesized (Both)
Animal vs. Plant
What are numbers 6, 7, 8, 9, 10, and their functions?
- Nucleus is filled with chromatin composed of DNA and proteins; site of mRNA and tRNA synthesis (Both)
- Smooth endoplasmic reticulum (ER) contains enzymes that synthesize lipids and detoxify certain hydrophobic molecules (Both)
- Rough endoplasmic reticulum (ER) functions in the synthesis, processing, and sorting of secretes proteins, lysosomal proteins, and certain membrane proteins (Both)
- Golgi complex processes and sorts secreted proteins, lysosomal proteins, and membrane proteins synthesized on the rough ER (Both)
- Secretory vesicles store secreted proteins and fuse with the plasma membrane to release their contents (Both)
Animal vs. Plant
What are numbers 11, 12, 13, 14, and their functions?
- Peroxisomes contain enzymes that break down fatty acids into smaller molecules used for biosynthesis and also detoxify certain molecules (Both)
- Cytoskeletal fibers form networks and bundles that support cellular membranes, help organize organelles, and participate in cell movement (Both)
- Microvilli increase surface area for absorption of nutrients from the surrounding medium (Animal)
- Cell wall, composed largely of cellulose, helps maintain the cell’s shape and provides protection against mechanical stress (Plant)
Animal vs. Plant
What are numbers 15, 16, 17, and their functions?
- Vacuole stores water, ions, and nutrients degrade macromolecules, and functions in cell elongation during growth (Plant)
- Chloroplasts, which carry out photosynthesis, are surrounded by a double membrane and contain a network of internal membrane-bounded sacs (Plant)
- Plasmodesmata are tubelike cell junctions that span the cell wall and connect the cytoplasms of adjacent plant cells (Plant)
Click to see an animal cell and some of its parts
