Honors Biology Chapter 7 Section 2 Eukaryotic Cell

Honors Biology Chapter 7 Section 2 Eukaryotic Cell Structure SC B -2. 2: SUMMARIZE THE STRUCTURES & FUNCTIONS OF ORGANELLES FOUND IN A EUKARYOTIC CELL(INCLUDING THE NUCLEUS, MITOCHONDRIA, CHLOROPLASTS, LYSOSOMES, VACUOLES, RIBOSOMES, ENDOPLASMIC RETICULUM [ER], GOLGI APPARATUS, CILIA, FLAGELLA, CELL MEMBRANE, NUCLEAR MEMBRANE, AND CYTOPLASM

Cytoplasm �Portion of the cell including everything inside cell membrane except nucleus �Cytosol: liquid portion of cytoplasm

NUCLEUS �Contains DNA with its coded instructions for making proteins so is the “control center” �most prominent structure seen with light microscope �Parts: Nucleolus Nuclear Envelope Nuclear Pores

NUCLEUS �Nucleolus dense region in nucleus produces subunits of ribosomes �Nuclear Envelope dbl membrane surrounding nucleus Outer layer contiguous with ER �Nuclear Pores holes thru envelope substances enter/leave nucleus thru these pores

DNA in NUCLEUS �chromatin: DNA bound to proteins (called histones) �Chromatin condenses into chromosomes when cell starts cell division

RIBOSOMES �assembly site for proteins � 2 subunits Small Large made separately in nucleolus exit nucleus thru nuclear pores join when making proteins

RIBOSOMES �Considering the function of ribosomes…. What types of cells do you think would have an abundance of ribosomes in them?

Endoplasmic Reticulum (ER) �Internal membrane system � 2 types: 1. Smooth ER (SER) 2. Rough ER (RER)

SER �make membranes for cell membrane other organs �detoxifies drugs alcohol poisons

SER �So… considering the functions of SER……what types of cells can you predict might have an abundance of SER?

RER �“rough” because outer membrane is studded with ribosomes �proteins made & released into RER where they are modified (sugar groups added making a glycoprotein) �most of proteins made here are destined for export out of cell

RER �What type of cell do you think would have lots of RER?

GOLGI APPARATUS �stack of curved membranes �usually found between ER and cell membrane �Function: modify, sort, & package material received from ER storage in cell or export out of cell

GOLGI

GOLGI �In what types of cells do you think there would be an abundance of Golgi bodies?

LYSOSOMES �membrane bound vesicle that has enzymes inside �Function: breakdown of macromolecules into smaller molecules which are then recycled in cytoplasm Where do these macromolecules come from?

Lysosomes �Where do lysosomes get the macromolecules? worn out organelles engulfed bacteria or cell debris

VACUOLES �membrane bounded storage facility �Protists (one-celled organisms) put food particles in a food vacuole until need the nutrients �plant cells have distinctive large central vacuole that stores water and some nutrients and helps plant maintain turgor when all cells have a filled central vacuole

Vacuoles

Food Vacuole

MITOCHONDRIA �convert chemical energy in sugars ATP (high energy molecule that temporarily stores energy in form cells can use) = cellular respiration �dbl membrane intermembrane space cristae : folds of inner membrane matrix: inside folds of cristae �has own DNA (maternal) & divides on own

Mitochondria

CHLOROPLASTS �in plant cells �capture energy in sunlight chemical energy (photosynthesis) �dbl membrane intermembrane space inner membrane folds into thylakoid discs stack of discs = granum space around grana = stroma �contain chlorophyll �+ DNA & divides on own

Chloroplasts

CYTOSKELETON �Function: internal structure & support movement of organelles & chromosomes anchors organelles and cells Made of proteins 3 types: 1. microfilaments 2. intermediate filaments 3. microtubules

MICROFILAMENTS �made of actin �supports cell shape �used by protist for movement � http: //highered. mcgraw- hill. com/sites/9834092339/student_view 0/chapter 4/animation_-_cytoplasmic_streaming. html

Microfilaments

Intermediate Filaments �used to move organelles around cytoplasm

MICROTUBULES �largest, strongest �shaped like hollow straws with units that spontaneously come together or fall apart �used to move organelles, chromosomes �made in centrosomes

CELL ANALOGY �Eukaryotic cells are like a city: each part has a job to be done Nucleus : mayor Mitochondria: power plant Lysosomes: city dump and recycling center SER: hospital Golgi: UPS store Cytoskeleton: roads & bridges Cell Membrane: border patrol @ city limits