Lesson 1 - Introduction Flashcards
True/ False: All present-day cells are descended from a single primordial ancestor.
True
True/False: Nucleic acids are capable of self-replication
True
RNA is capable of catalyzing what?
Chemical Reactions
True/False: RNA is able to both serve as a template for, and to catalyze its own replication.
True
Genes:
are segments of DNA that encode proteins or RNA - Functional units of inheritance.
Transcription:
Nucleotide gene sequence is copied into RNA.
Translation:
Nucleotide sequence of RNA is used to specify the order of amino acids in a protein.
When did the the first cell arose?
When self-replicating RNA was enclosed in a phospholipid membrane.
Phospholipids:
Basic components of all present-day biological membranes.
True/False: Phospholipids are amphiphatic (Have two Functions)?
True,
Hydrophobic (Water-Insoluble) hydrocarbon chains joined to Hydrophilic (Water-Soluble) head groups that contain phosphate.
When in water phospholipids spontaneously aggregate into a bilayer.
True/False: Cell use adenosine 5’-triphosphate (ATP) as their source of metabolic energy.
True
What are the 3 stages of the mechanisms of generation of ATP.
Glycolysis: Anaerobic (no oxygen).
- Glucose -> 2 C3H6O3 (Lactic Acid) = 2 ATPs
- Glucose is not completely broken down
Photosynthesis: Some cells get energy from the sun, no longer need preformed organic molecules.
- 6 CO2 + 6 H2O->(sun)->C6H12O6(Glucose) + 6 O2
- Generates Oxygen.
Oxidative Metabolism: Oxygen is involved.
- Glucose + 6 O2 -> 6 CO2 + 6 H2O = 36-38 ATPs
- Completely breaks down glucose.
*Glucose = C6H12O6
What are the two types of cells?
Prokaryotic (Bacteria) : lack a nuclear envelope
Eukaryotic: have a nucleus that separates genetic material from cytoplasm.
Prokaryotic:
No Nucleus
Diameter: ~1um
No Cytoplasmic Organelles
DNA Content (Base Pairs) : 110^6 to 510^6
Chromosomes: Singular Circular DNA Molecule
Eukaryotic:
Nucleus: Yes
Diameter: 10-100um
Cytoplasmic Organelles: Yes
DNA Content (Base Pairs) : 1.510^7 to 510^9
Chromosomes: Multiple Linear DNA Molecules
What are the 3 present-day prokaryotic?
Archaebacteria: many live in extreme environments.
Eubacteria: a large group that live in a wide range of environments.
Cyanobacteria: the group in which photosynthesis evolved, are the largest and most complex prokaryotes.
Escherichia Coli (E. Coli) :
- It has a rigid cell wall of polysaccharides and peptides
- Beneath the cell wall is the plasma membrane, a phospholipid bilayer with associated proteins.
- E. Coli DNA is a single circular molecule in the nucleoid which is not surrounded by a membrane separating it from the cytoplasm.
- The cytoplasm contains approximately 30,000 ribosomes (sites of protein synthesis).
Eukaryotic: Nucleus
The largest organelle.
Contains the linear DNA molecules.
Site of DNA replication and RNA synthesis.
Eukaryotic: Mitochondria
Site of Oxidative Metabolism
- Site that uses glucose
- Have their own DNA, which encodes some of their components.
- Like bacteria, they reproduce by diving in two.
- Similar to bacteria in size.
Eukaryotic: Choloroplasts
Only in plant cells
Site of photosynthesis
- Have their own DNA, which encodes some of their components.
- Like bacteria, they reproduce by diving in two.
-Similar to bacteria in size.
Eukaryotic: Lysosomes and Peroxisomes
Specialized metabolic compartments for the digestion of macromolecules and for various oxidaitve reactions.
Have enzymes that help break down…(?)
Eukaryotic: Vacuoles
Only in plant cells
Several functions such as digestion of macromolecules and storage of waste products and nutrients.
Eukaryotic: Endoplasmic Reticulum
Network of intracellular membranes, extending from the nuclear membrane throughout the cytoplasm.
It functions in processing and transport of proteins and lipid synthesis.
Eukaryotic: Golgi Apparatus
In it proteins are further processed and sorted for the transport to their final destinations.
Also serves as a site of lipid synthesis
-In plant cells - the synthesis of some polysaccharides that compose the cell wall.
Eukaryotic: Cytoskeleton
Network of protein filaments extending throughout the cytoplasm.
- Provides structural framework
- Determines cell shape and organization
- Involved in movement of whole cells, organelles, and chromosomes during cell division.
True/False: Eukaryotic organelles are thought to have arisen by endosymbiosis.
True,
Endosymbiosis: prokaryotic cells living inside the ancestors of eukaryotes.
True/False: DNA is replicated when the organelle divides.
True,
The genes are transcribed within the organelle and translated on organelle ribosomes.
True/False: Many eukaryotes are unicellular organisms.
True,
Simplest eukaryotes: fungi
True/False: Some multicellular algae can go from single cells to multicellular organisms.
True,
The amoeba Dictyostelium Discoideum can also alternate depending on the availability of food.
What are the 3 main tissue systems that plants have?
- Ground Tissue:
- Parenchyma Cells: Site of metabolic reactions, including photosynthesis.
- Collenchyma and Sclerenchyma: Have thick cell walls and provide structural support.
- Dermal Tissue: Covers the surface of the plant; forms a protective coat and allows absorption of nutrients.
- Vascular Tissue (Xylem and Phloem): Elongated cells which transport water and nutrients throughout the plant.
How many main tissue types do animals have?
They have 5:
- Epithelial Cells
- Connective Tissues
- Blood
- Nervous Tissue
- Muscle Cells
Animal : Epithelial Cells
Form sheets that cover the surface of the body and lien internal organs.
Animal : Connective Tissue
Include bone, cartilage, and adipose tissue.
Loose connective tissue is formed by fibroblasts.
Animal : Blood
Has several different types;
- Red blood cells (Erythrocytes) - function in oxygen transport.
- White blood cells: functionin infalmmatory reactions adn the immune response.
- Granulocytes
- Monocytes
- Macrophages
- Lymphocytes
Animal : Nervous Tissue
Is composed of supporting cells and nerve cells, or neurons, and various types of sensory cells.
Animal : Muscle Cells
Responsible for the production of force and movement.
