LSU Biol 1201 LiCata Exam 2 Fall 2025 Questions And Answers Verified 100% Correct

LSU Biol 1201 LiCata Exam 2 Fall 2025 Questions And Answers Verified 100% Correct Mitochondria - ANSWER --Site of cellular respiration, generation of ATP -Contain own ribosomes and DNA -Was originally bacteria -Smooth outer membrane and an inner membrane folded into cristae -Inner membrane creates 2 compartments: intermembrane space and mitochondrial matrix -Different enzymes, and different metabolic reactions, are in each compartment Chloroplast - ANSWER --Sites of photosynthesis -Contain own DNA and ribosomes -Originally a bacteria -Contain green pigment chlorophyll, plus the enzymes and molecules of photosynthesis -Has 2 membranes -Structure includes: Thylakoids- membranous sacs, stacked to form granum Stroma- the internal fluid Peroxisomes - ANSWER --Have a single membrane -Produce hydrogen peroxide and convert it to water -Perform many metabolic reactions -Unknown how they are related to other organelles Cytoskeleton - ANSWER --A network of fibers extending throughout the cytoplasm -Composed of three types of molecular structures -Microtubules -Microfilaments -Intermediate filaments Microtubules - ANSWER --Part of cytoskeleton -Thickest fibers, made of Alpha and Beta tubulin Microfilaments - ANSWER --Part of cytoskeleton -Thinnest fibers, made of actin, also called actin filaments intermediate filaments - ANSWER --Part of the cytoskeleton -intermediate sized, made of a variety of proteins Centrosomes and Centrioles - ANSWER --In many cells microtubules grow out from a centrosome near the nucleus -the centrosome is a "microtubule-organising center" -in animal cells the centrosome has a pair of centrioles each with nine triplets of microtubules arranged in a ring cilia and flagella - ANSWER --microtubules control the beating of cilia and flagella, locomotor appendages of some cells -cilia and flagella differ in beating patterns cilia and flagella structure - ANSWER --A core of microtubules sheathed by the plasma membrane -A basal body that anchors it -A motor protein called dynein which drives the bending movements Actin and Myosin - ANSWER --Microfilaments that function in cellular motility use myosin in addition to actin -in muscle cells thicker filaments composed of myosin interdigitate with the thinner actin fibers -They drive amoeboid movement via Pseudopodia (cellular extensions) -Cytoplasmic streaming = a circular flow of cytoplasm within cells, is also aactin myosin driven Extracellular structures - ANSWER --Cell walls of plants -The extracellular matrix (ECM) of animals -Intercellular junctions cell walls of plants - ANSWER --Extracellular structure that distinguishes plant cells from animal cells -Prokaryotes, fungi, and some protists also have cell walls -Protects the plant cell, maintains shape, and prevents excessive uptake of water -Made of cellulose fibers along with other polysaccharides and protein Extracellular Matrix (ECM) of animal cells - ANSWER --Animal cells lack cell walls but are covered by elaborate (ECM) -Made up of glycoproteins such as collagen, proteoglycans, and fibronectin -ECM proteins bind to receptor proteins in the plasma membrane called integrins -Functions of ECM= support, adhesion, movement, regulation cell junctions - ANSWER --Neighboring cells often adhere, interact, and communicate Cell junction types - ANSWER --Plasmodesmata= plants only, transport of material* between cells -Tight junctions= Hold cells together -Desmosomes- hold cells together -Gap Junctions= transport material between cells Materials=*(water, ions, small molecules, rarely macromolecules) fluidity of membranes - ANSWER --Higher temp= more fluid -More unsaturated fatty acids= more fluid -more saturated fatty acids= less fluid -Ability to change lipid compositions in response to temp evolved in organisms tat live where temps vary -Cholestrerol= allows for quick responses to temp in cells Membrane proteins - ANSWER --Proteins determine most of the membrane's functions -Membranes have distinct outside and inside faces mostly due to proteins -Peripheral proteins= are bound to the surface of the membrane -Integral proteins= penetrate the hydrophobic core(If they span the mebrane then they are transmembrane proteins) -Six major functional types of membrane proteins 6 major functions of membrane proteins - ANSWER --Transport -Enzymatic activity -Signal transduction -Cell-cell recognition -Intercellular joining -Attachment to the cytoskeleton and extracellular matrix (ECM) Membrane carbohydrates and cell-cell recognition - ANSWER --Cells recognize each other by binding to surface membrane molecules (often containing carbohydrates)