Biology Unit 2 Cell Structure and Functions

Today’s Plan: Cellular Organelles Surface Area : Volume Membrane Transport Practice Questions Unit 2 Q&A Nucleus Structure: • Double membrane (nuclear envelope) with pores Functions: • Stores genetic information (DNA) • Synthesis of RNA • Ribosome subunit assembly Rough ER Structure: • Membrane studded with ribosomes attached to nuclear envelope Functions: • Site of membrane-bound protein and secreted protein synthesis • Cell compartmentalization • Mechanical support • Role in intracellular transport Structure: • Folded, tubelike structure (cisternae) Functions: • Detoxification • Calcium Storage • Lipid synthesis Cellular Organelles Structure: • Membrane-bound structure composed on flattened sacs (cisternae) Functions: • Folding and chemical modification of synthesized proteins • Packaging protein traffic Golgi Complex Structure: • Composed of rRNA and protein • Large & small subunits • Types: bound or free (cytoplasmic) Functions: • Protein synthesis Ribosomes Smooth ER Mitochondria Structure: • Double membrane (outer: smooth; inner: highly folded) Functions: • Site of oxidative phosphorylation (cristae/inner membrane) • Site of Krebs Cycle (matrix) Cellular Organelles Structure: • Double outer membrane (thylakoid sac stacked: grana and fluid: stroma) Functions: • Site of photosynthesis • Thylakoid: Light Reactions • Stroma: Calvin-Benson Cycle Chloroplast Lysosome Mitochondria Structure: • Double membrane (outer: smooth; inner: highly folded) Functions: • Site of oxidative phosphorylation (cristae/inner membrane) • Site of Krebs Cycle (matrix) Structure: • membrane-enclosed sacs that contain hydrolytic enzymes Functions: • Intracellular digestion (recycle cell organic materials & programmed cell death: apoptosis) Cellular Organelles Structure: • membrane-bound sac Functions: • storage and release of macromolecules and cellular waste products • Central: water retention – turgor pressure • Contractile: osmoregulation (protist) • Food: phagocytosis, fuse with lysosome Vacuole Structure: • Double outer membrane (thylakoid sac stacked: grana and fluid: stroma) Functions: • Site of photosynthesis • Thylakoid: Light Reactions • Stroma: Calvin-Benson Cycle Chloroplast Surface Area: Volume Smaller cells typically have a higher surface area-to-volume ratio and more efficient exchange of materials with the environment. Facilitated Diffusion Simple Diffusion • • • • • • Passive Transport, No NRG Down concentration gradient Small, Nonpolar No transport protein needed Examples: CO2, O2, N2, steroids Small amount of H2O leak through membrane Passive Transport, No NRG Down concentration gradient Small Molecules Requires transport protein Channel vs. Carrier protein • Example: water, Na+, K+, Ca+ • • • • Active Transport • Requires input of NRG • Against concentration gradient • Requires transport protein (carrier protein) • Example: Na+, K+, Ca+, H+ Membrane Transport Plasma Membrane Composed of: • Phospholipids • Membrane Proteins • Glycolipids/Glycoproteins • Cholesterol Facilitated Diffusion Simple Diffusion Passive Transport, No NRG Down concentration gradient Small, Nonpolar No transport protein needed Examples: CO2, O2, N2, steroids Small amount of H2O leak through membrane • • • • • • Passive Transport, No NRG Down concentration gradient Small Molecules Requires transport protein Channel vs. Carrier protein • Example: water, Na+, K+, Ca+ • • • • Active Transport • Requires input of NRG • Against concentration gradient • Requires transport protein (carrier protein) • Example: Na+, K+, Ca+, H+ Membrane Transport Endocytosis • • • • Import of materials Phagocytosis: Cellular Eating Pinocytosis: Cellular Drinking Receptor-Mediated: Endocytosis Exocytosis • Export of materials • Rough ER (synthesize)  Golgi complex (package/modification)  Plasma Membrane Hypertonic Solution Isotonic Solution Hypotonic Solution • HIGH solute concentration • LOW free water concentration • EQUAL solute concentration (as other solution) • EQUAL free water concentration (as other solution) • LOW solute concentration • HIGH free water concentration • GAINS water from hypotonic solution • Equal water movement into and out of solution Osmosis • LOSES water to hypertonic solution Multiple Choice Practice A common laboratory investigation involves putting a solution of starch and glucose into a dialysis bag and suspending the bag in a beaker of water, as shown in the figure below. The investigation is aimed at understanding how molecular size affects movement through a membrane. Which of the following best represents the amount of starch, water, and glucose in the dialysis bag over the course of the investigation? Multiple Choice Practice A common laboratory investigation involves putting a solution of starch and glucose into a dialysis bag and suspending the bag in a beaker of water, as shown in the figure below. The investigation is aimed at understanding how molecular size affects movement through a membrane. Which of the following best represents the amount of starch, water, and glucose in the dialysis bag over the course of the investigation? FRQ Practice (2018 #6) Free Response Practice: Cystic fibrosis is a genetic condition that is associated with defects in the CFTR protein. The CFTR protein is a gated ion channel that requires ATP binding in order to allow chloride ions (Cl-) to diffuse across the membrane. (b) Identify the most likely cellular location of the ribosomes that synthesize CFTR protein. (c) Identify the most likely cellular location of a mutant CFTR protein that has an amino acid substitution in the ATP-binding site. Nucleus Structure: • Double membrane (nuclear envelope) with pore5 Function5: Store5 genetic information (DNA) • Synthe5i5 of RNA • Ribo5ome 5ubunit a55embly Rough ER Structure: • Membrane 5tudded with ribo5ome5 attached to nuclear envelope Function5: • Site of membrane-bound protein and 5ecreted protein 5ynthe5i5 Cell compartmentalization Mechanical 5upport • Role in intracellular tran5port Smooth ER Structure: • Folded, tubelike 5tructure (ci5ternae) Function5: Detoxification • Calcium Storage Lipid 5ynthe5i5 Cellular Organelles Structure: • Membrane-bound 5tructure compo5ed on flattened 5ac5 (ci5ternae) Structure: Compo5ed of rRNA and protein • wirge & 5mall 5ubunit5 • Type5: bound or free (cytopla5mic) Function5: Folding and chemical modification of 5ynthe5ized protein5 Packaging protein traffic Function5: • Protein 5ynthe5i5 Golgi Complex Ribosomes Lysosome Mitochondria Structure: • Double membrane (outer: 5mooth: inner: highly folded) Structure: • membrane-enclo5ed 5ac5 that contain hydrolytic enzyme5 Function5: Site of oxidative pho5phorylation (cri5tae/inner membrane) • Site of Kreb5 Cycle (matrix) Function5: • Intracellular dige5tion (recycle cell organic material5 & programmed cell death: apopto5i5) - Cellular Organelles Structure: • membrane-bound 5ac Function5: 5torage and relea5e of macromolecule5 and cellular wa5te product5 Central: water retention - turgor pre55ure • Contractile: o5moregulation (proti5t) Food: phagocyto5i5, fu5e with ly5o5ome Structure: ... _ • Double outer membrane (thylakoid 5ac 5tacked: grana and fluid: 5troma) Function5: Site of photo5ynthe5i5 Thylakoid: Light Reaction5 • Strama: Calvin·Ben5on Cycle Chloroplast Vacuole Surface Area: Volume Volume: V = j1tr3 Surface Area: S = 41tr2 s Volume: V = s3 Surface Area: 5 = 6s2 H _ h ... Volume: V• LWH SurfaceArea:Ss 2LH + 2LW+ 2WH w Volume: V = x r2 h or V = Bh S = 2u2 + 2,vh Surface Area: s Smaller cells typically have a higher surface area-to-volume ratio and more efficient exchange of materials with the environment. Plasma Membrane Composed of: • Phospholipids • Membrane Proteins • Glycolipids/Glycoproteins • Cholesterol i i Passive Transport, No NRG Down concentration gradient Smal l, Nonpola r No transport protein needed Examples: CO2, 02, N2, steroids Small amount of H20 leak through membrane • • • • i i Fac l tated D ffusion i S mple D ffusion Act ive Transport Passive Transport, No NRG Down concentration gradient Small Molecules Requires transport protein Channel vs. Carrier protein Example: w ater, Na•, K•. Ca• • • Requires input of NRG Against concentration gradient Requires transport protein (carrier protein) Example: Na•. K•.Ca·. H ' • • Membrane Transport Bulk Transport. Endocytosis • • Import of materials Phagocytosis: Cellula r Eating Pinocytosis: Cellula r Drinking Receptor-Mediated: Endocytosis:::.. • Exocytosis Export of materials Rough ER (synthesize) ➔ Golgi complex (package/mod ification) ➔ Plasma Membr ane • --.- -��.�;''-- c..-::!..::. .. 6:;..... I ,, I Low •olut• concentr•tlon numberor watermolecules•24 numberof solutemolecules ■ O I � ci "' � � ci ce � � � I I I � i, � 4i' ci ce ci 4i' � � � � . number of "-• water molecules ■ 24 I •"' • ,, High solllte concentration number of water molecules ■ 24 numberof solutemolecules•5 � +� I -,� � £ • • HIGH solute concentration LOW free water concentration • GAINS water from hypotonic solution • • • • • __.....,. • -• ---• -� • • • :u.· • • • •• �-- .... lie .... • HM'JH W11lR l(}.,J W11lR ffiHNIIN. ffiHNIIN. Isotonic Solution Hypertonic Solution • • m;mberof tr.. water molecules■ 4 --+ • �• ·-- •tK••- EQUAL solute concentration (as other solution) EQUAL free water concentration (as other solution) Equal water movement into and out of solution �HR M(MS � 05t(05!S IROO\ HIGH IO IO,,J W11lR ffiHNIIN. Hypotonic Solution • • LOW solute concentration HIGH free water concentration LOSES water to hypertonic solution Osmosis I v� � �: I