Chapter 4 Cell Structure and Function

4.1 The Cell Theory Tenets of Modern Cell Theory –Every living organism is made of –The smallest living organisms are _________ and _____ are the functional units of multicellular organisms –All cells arise from______________

Cell Size –Most cells are small, ranging from _______ micrometers in diameter. Some are large Size/Functions: –____________ ___________ with the environment. –No part of the cell can be far away from the external environment 4.2. Basic Attributes of Cells

Common Features: A ________ ________________ encloses all cells and regulates material flow

4.2. Basic Attributes of Cells Common Features: ___________ is the fluid interior where a cell’s metabolic reactions occur –Contains _________ –Fluid portion (_________) contains ________ _________________

4.2. Basic Attributes of Cells Common Features: All cells use ___ _____________ ____ as a hereditary blueprint All cells use ___ _____________ to copy DNA to make proteins

4.2. Basic Attributes of Cells Common Features: All cells obtain energy and nutrients from _____ _____________ All cells use common _____ ____________ to build the molecules of life

4.2. Basic Attributes of Cells There Are Two Basic Types of Cells: ____________________________

4.2. Basic Attributes of Cells Eukaryotic –True nucleus

4.3. Major Features of Eukaryotic Cells

Eukaryotic cells are > A variety of membrane- enclosed ___________ perform specific functions

Cell Walls _______________ ____________ of bacteria, plants, fungi, and some protists Composed of _______________: –__________ (plants and some protists) –______ (fungi) Function:

Cell Walls Cell walls in plants may have multiple layers –_______________ in plants are outermost –________________ are innermost –Cell walls of adjacent cells joined by ______________

The Cytoskeleton Cytoskeleton forms a network of _____________ within the cytoplasm Provides _____________ _______________ Three types of proteins:

The Cytoskeleton Main functions of cytoskeleton

Cilia and Flagella Extensions of the ___________ ________________ Composed of _____________ in a “9+2” arrangement formed by _____________ which become membrane-anchored structures called _________________ Long pairs of microtubules slide along each other ___________ causing movement of cilia and flagella Cilia are ______________ and ___________while flagella are ___________ but _____ in any cell

Cilia and Flagella Functions –Cilia or flagella may be used _______________ –Cilia may be used to

The Nucleus - The nucleus is an organelle that contains three major parts

The Nucleus -_____________ ____________ separates chromosomes from cytoplasm –Envelope is a _______ __________________ ____ for transport. Outer membrane is studded with

The Nucleus The nucleus contains DNA in various configurations –Compacted ________________ (during cell division) –Diffuse __________ (as DNA directs reactions through an ____ intermediate by coding for ________)

The Nucleus Darker area within the nucleus called the ______________ –Functions as the site of ________ _____________________ –Ribosomes synthesize __________ Ribosomes –Small, roundish (not membrane) structures made up by _______ __________________ Made up of 2 subunits Some _______ in the cytoplasm Others

System of Membranes Membrane system includes the plasma membrane and organelle membranes

System of Membranes Plasma membrane Plants, fungi, and some protists additionally have a _________ outside the plasma membrane

System of Membranes __________ are membranous sacs that transport substances among the separate regions of the membrane system

System of Membranes _______________________ forms a series of enclosed, interconnected channels within cell There are two forms of ER –-

System of Membranes __________________ has no ribosomes –Contains enzymes that ______________ (in liver cells) or synthesizes _______________

System of Membranes __________________ is studded with ribosomes on outside –Produces _____________________________ _____________________________________ (export)

System of Membranes _______________ is a set of stacked flattened sacs –Receives proteins from ER (via transport vesicles) and sorts them by destination _________________ –__________ some molecules (e.g. proteins to glycoproteins) –_______________ into vesicles for transport (export). Many in secretory cells

System of Membranes Three fates of substances made in the membrane system: 1.- –Figure 4-14 illustrates this process for antibodies, proteins produced by white blood cells to inactivate foreign disease- causing agents

System of Membranes 2.Digestive proteins (lysozyme) made in RER, travel through Golgi, and are packaged as – Lysosomes fuse with food vacuoles and digest food into basic nutrients Destroy bacterial cells, viruses, digestive worn out organelles and whole cells

System of Membranes 3.Membrane proteins and lipids made in ER, travel through Golgi, and …

Vacuoles Serve Many Functions Fluid-filled sacs with a ______ membrane Functions of vacuoles –___________ vacuoles in freshwater organisms used to collect and pump water out

Vacuoles Serve Many Functions Functions of vacuoles (continued) –Plant _______________ used in several ways Maintain.. Store … Provide …___________ on cytoplasm to keep cells rigid

Mitochondria Extract Food Energy Mitochondrion (pl. -dria) _____________________ of the cell ___________, (or tubular sacs of double-membranes) Outer membrane:.. Intermembrane compartment Inner membrane is folded into … Internal matrix packed with enzymes for..

Mitochondria Extract Food Energy Contains its own DNA Mitochondria may be remnants of free-living prokaryotes (_______________________) –(Lynn Margulis – Univ of MAs.): –Eukaryotes evolved from two _________ in a symbiotic relationship Internal prokaryotes became:

Mitochondria Extract Food Energy Function as the “powerhouses of the cell”

Chloroplasts With double membrane –__________ membrane –__________ membrane encloses the ______ space Stacked hollow membranous sacs ( ) within stroma are called …

Chloroplasts Site of Photosynthesis: __________________ with pigments that capture ___________ ______________ and make ________ –Chlorophylls a and b .. –Carotenoids alpha and beta .. thylakoid

Plants Use Plastids for Storage Plastids found only in Surrounded by a double membrane

Plants Use Plastids for Storage Functions –_________ for photosynthetic products like starch –_________ of pigment molecules giving color to ripe fruit

4.4. Major Features of Prokaryotic Cells Most prokaryotic cells (bacteria) … Shapes:..

4.4. Major Features of Prokaryotic Cells Specialized surface features –Cell wall is usually present: of –Infectious bacteria may have polysaccharide adhesive ___________ and ______ __________ on their surfaces –________________. Protein projections in some bacteria that further enhance adhesion. –Some bacteria are propelled by _______________

4.4. Major Features of Prokaryotic Cells Specialized structures within their cytoplasm (few) –.. –Small rings of DNA (_______________)

chromosome (nucleoid region) pili ribosomes food granule prokaryotic flagellum capsule or slime layer cell wall plasma membrane cytoplasm plasmid (DNA)

Prokaryotic Cells …Specialized structures within their cytoplasm (few) –____nuclear membrane or membrane-bound organelles present –Some have internal membranes used to ___________________ –Cytoplasm may contain _______________

5 micrometers 10 micrometers 50 micrometers cilia 0.5 micrometers mitochondrion mitochondria cilia nucleus contractile vacuole Paramecium Light microscopeTransmission electron microscope Scanning electron microscope