BIO 101 Test 2 Study Guide Flashcards
(31 cards)
What is a cell?
A cell is the basic unit of life, capable of performing all essential life processes.
What is cell theory?
A fundamental concept in biology that was discovered by Schwann and Schleiden. It is composed of three parts that were discovered in the 19th century:
1) All living organisms are composed of one or more cells.
2) The cell is the basic unit of structure and organization in organisms.
3) All cells arise from pre-existing cells. Came up by Virchow.
An extra two parts are added in modern cell thory
4) Cells contain DNA that is passed down during cell division.
5) All cells are basically the same in chemical composition and metabolic activities.
What are the similarities between eukaryotic and prokaryotic cells?
Similarities:
1) Both have DNA.
2) Both have a cell/plasma membrane.
3) Both have a cytoplasm.
4) Both have ribosomes.
5) Both can reproduce.
6) Both perform metabolism.
7) Both can respond to stimuli.
8) Both can grow.
9) Both maintain homeostasis.
10) Both are enclosed by a membrane.
What are the differences between eukaryotic and prokaryotic cells?
Eukaryotic cells:
1) Has a true nucleus with a nucleus envelope
2) Larger
3) Has membrane-bound organelles (e.g. mitochondria)
4) More complex in structure and function
5) Animals, plants, fungi, protists
6) Plant cell wall
Prokaryotic cells:
1) No true nucleus; DNA floats in nucleoid region
2) Smaller
3) No membrane-bound organelles
4) Less complex in structure and function
5) Archaea, bacteria
6) Peptidoglycan is what composes the cell wall
Describe the make-up of a bacterial cell.
Cell wall: provides structure and protection
Plasma membrane: regulates entry and exit of substances
Cytoplasm: site of metabolic reactions
Nucleoid: region containing DNA
Ribosomes: protein synthesis (creating something new with different combos)
Describe the make-up of animal cells.
Nucleus: contains genetic material
Mitochondria: powerhouse of the cell; energy production
Endoplasmic Reticulum (ER): synthesizes proteins and lipids
Golgi apparatus: modifies and packages proteins
Lysosomes: digests waste materials
Describe the make-up of plant cells.
Cell wall: provides rigidity and protection
Chloroplasts: sites of photosynthesis
Central vacuole: maintains cell turgidity
Plasma membrane: regulates substance movement
Nucleus: contains genetic material
What is the endomembrane system?
The endomembrane system is a network of membrane within the cell that work together to modify, package, and transport lipids and proteins.
What are the steps of the endomembrane system?
Rough ER: Synthesizes proteins.
Smooth ER: Synthesizes lipids.
Golgi Apparatus: Modifies and packages proteins and lipids.
Vesicles: Transport materials between organelles and to the plasma membrane .
What are the differences between plant and animal cells?
Plant Cells:
1) Have a cell wall and chloroplasts.
2) Contain a large central vacuole.
3) Perform photosynthesis.
Animal Cells:
1) Lack a cell wall and chloroplasts.
2) Have small, multiple vacuoles.
3) Perform cellular respiration.
List each type of cell-to-cell junctions.
Tight Junctions
Adherens Junctions
Desmosomes
Gap Junctions
What are tight junctions?
Tight Junctions: Seal cells together to prevent leakage.
What are adherens junctions?
Adherens Junctions: Connect actin filaments between cells.
What are desmosomes?
Desmosomes: Anchor cells together for mechanical strength.
What are gap junctions?
Gap Junctions: Allow communication between cells through channels.
List the different components of the cytoskeleton.
Microtubules
Intermediate Filaments
Microfilaments (Actin Filaments):
What are microtubules?
Microtubules: Provide structural support and facilitate intracellular transport.
What are intermediate filaments?
Intermediate Filaments: Maintain cell shape and anchor organelles.
What are microfilaments?
Microfilaments (Actin Filaments): Involved in cell movement and shape changes.
What is an enzyme and how do they function?
An enzyme is a protein that accelerates chemical reactions without being consumed. They function by lowering the activation energy required for reactions.
What factors influence enzyme activity?
Factors include:
Temperature: Optimal temperature increases activity; extreme temperatures can denature enzymes.
pH: Each enzyme has an optimal pH range.
Substrate Concentration: Higher concentrations can increase reaction rates p to a point.
What is an inhibitor? Explain its importance in negative feedback loops.
An inhibitor is a molecule that decreases enzyme activity. In negative feedback loops, inhibitors regulate metabolic pathways by reducing the production of substances when they are abundant, maintaining homeostasis .
List two types of energy, explain the laws of thermodynamics.
Kinetic Energy: Energy of motion.
Potential Energy: Stored energy.
Laws of Thermodynamics:
First Law: Energy cannot be created or destroyed, only transformed.
Second Law: Entropy (disorder) of an isolated system always increases over time.
What is ATP?
ATP (Adenosine Triphosphate) is the primary energy carrier in cells. It stores and transfers energy for various cellular processes, including muscle contraction and protein synthesis .
