CELLS Two main types of cells are and _. A. Prokaryotic; eukaryotic B. Bacterial;...

CELLS

Two main types of cells are ______ and _______.

A. Prokaryotic; eukaryotic

B. Bacterial; animal

C. Nerves; muscles

D. Plant; animal

© 2009 W.W. Norton & Company, Inc. DISCOVER BIOLOGY 4/e 43

The boundary structure that physically defines a cell is the .

A.Cell wall

B.Selective permeability

C.Plasma membrane

D.Protein coat


Where is the secreted protein insulin synthesized?

A. In the Golgi apparatusB. On the rough ERC. On ribosomes in the cytoplasmD. In the nucleus


Cell Is the Basic Unit of Life Cell theory: An organism can be one celled or

multicellular

Multicellular organisms have billions of cells

Humans have over 200 types of cells

Hooke first described cells in 1665 Schleiden (1838) recognized plant cells Schwann (1839) reported animal cells

cells are too small to be viewed by the naked eye, one way to increase resolution is to increase magnification, such as by using a microscope

two major types: Prokaryotic: bacteria

and archae lacks a nucleus Without a system of

internal membranes

Eukaryotic: algae, fungi, plants, animals

has a nucleus has internal

membrane-bound compartments

Cell types


ProkaryotesLittle internal organizationMuch smaller than eukaryotes


Figure 5.2

■ EukaryotesDNA contained in nucleus Membrane‑enclosed

organellesInternal compartments

for special functions

Different eukaryotic cells

Protist, fungi, plants= cell wall beyond the plasma membrane

Protist, plants= chloroplasts Plants= central vacuoleAnimals= centrioles

Cellular structure is organized:

Cell Structure


The Plasma Membrane

• Defines the boundary of the cell

• Consists of a bilayer of lipids with proteins for communication with external environment– Selective permeability

– and act as markers= blood types

• Fluid mosaic model– Mobility of components of the membrane


Nucleus: The Administrative Office command and control

center of the cell stores hereditary

information: DNA Surrounded by a

double-membrane nuclear envelope

Nuclear pores are gateways for molecules

Nucleolus dark-staining region of the nucleus contains the genes that code for the rRNA

(ribosomal RNA) that makes up the ribosomes the subunits leave the nucleus via the nuclear

pores and the final ribosome is assembled in the cytoplasm


Mitochondrion: Power Plant Double‑membrane organelle Inner membrane folded

into cristae Harnesses energy from

chemical breakdown Cellular respiration

Produce ATP


Chloroplast: Photosynthesis Double‑membrane

organelle Contains grana,

made of thylakoids Converts CO2

and H2O into sugars using light

Chlorophyll enables photosynthesis

Figure 5.10


The Endoplasmic Reticulum: The Factory Floor

Figure 5.4

Interconnected tubes and flattened sacs

Rough ER Ribosomes Makes membrane

and secreted proteins Smooth ER

Makes membrane vesicles


Golgi: Shipping Department

Stacked, flattened

membrane sacs

Processes new

proteins and lipids Adds specific

chemical groups

Targets them

to their destinations


Vesicles: Movement in the Cell Vesicles

Membrane‑enclosed sacs Transport vesicles

Moving substances from one location to another


Lysosomes: Clean-up Crew Small spherical organelles Contain enzymes to break down macromolecules Release simple sugars, amino acids,

and fats to be recycled To clear cell of damaged organelles As a source of food To destroy invading bacteria

Derivate from membranes in the cell The functions are:

1. detoxify harmful byproducts of metabolism

2. convert fats to carbohydrates in plants seeds for growth

Peroxisomes: Detoxy centers


The Central Vacuole: Storage

Figure 5.8

A specialized structure in plants and fungi Breaks down substances Stores chemicals

for later use Fills with water to

provide rigidity

27

Cytoskeleton:

Gives the cell its shape

Provides internal support

Is responsible for movementmicrotubule

intermediatefilament

microfilament


Movement

Used as tracks for vesicle movement or the whole cell


Cilia and Flagella Cilia beat in unison like oars

Flagella beat like whips

Centrioles • complex structures • In animal cells and

protists• Functions:

• anchor locomotory structures

• assemble microtubules near the nuclear envelope for the cell division

– found in• Plants• Fungi• protists

– function in:• Protection• maintaining cell shape• preventing excessive water

loss/uptake

Cell Wall

• Outside the plasma membrane

• in animal cells

• mixture of proteins: Collagen and elastin for protective layer

• ECM coordinates cells functioning as tissues

Extracellular matrix (ECM)


Evolution of Organelles

• Eukaryotes most likely evolved from prokaryotes– Larger prokaryotes ingested smaller prokaryotes

• Free-living mitochondria and chloroplasts were captured – Formed an endosymbiotic relationship with the host cell

Extra credit…. Make flash cards with all the following terms

Cell

Chloroplast

Chromosome

Cilium

Ribosome

Rough ER

Smooth ER

Vacuole

Vesicle

Cytoplasm

Cytoskeleton

Eukaryote

Flagellum

Fluid mosaic model

Golgi apparatus

Extra cellular matrix

Lysosome

Mitochondrion

Nuclear envelope

Nucleolus

Nucleus

Organelle

Plasma membrane

Prokaryote

peroxysome

Review Question1: Cell theory includes the principle thatA) cells are the smallest living thingsB) all cells are surrounded by cell wallsC) all organisms are made up of many cells D) Nothing smaller than an organelle is considered alive.

2: The plasma membrane is:A) carbohydrate layer that to protect B) double lipid layer with proteins inserted in itC) thin sheet of structural proteins that lines the inside of some body cavitiesD) composed of blood plasma that has solidified into a protective barrier.

3: Organisms that have cells with cytoplasm and no organelles are called ______________, and organisms whose cells have organelles and a nucleus are called ______________

A) cellulose, nuclearB) flagellated, streptococcalC) eukaryotes, prokaryotesD) prokaryotes, eukaryotes

4: Within the nucleus of a cell you can find ________

5: The endomembrane system within a cell includesA) cytoskeleton and ribosomes.B) prokaryotes and eukaryotesC) endoplasmic reticulum and GolgiD) mitochondria and the chloroplasts.

6: Which of the following statements is true?A) All cells have a cell wall for protection and structure.B) Eukaryotic cells in plants and fungi, and all prokaryotes, have a

cell wall.C) There is a second membrane composed of structural

carbohydrates surrounding all cells.D) Prokaryotes and all cells of eukaryotic animals have a cell wall.

CELLS Two main types of cells are and _. A. Prokaryotic; eukaryotic B. Bacterial;...

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Transcript of CELLS Two main types of cells are and _. A. Prokaryotic; eukaryotic B. Bacterial;...

CELLS Two main types of cells are ______ and _______. A. Prokaryotic; eukaryotic B. Bacterial;...

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CELLS Two main types of cells are and _. A. Prokaryotic; eukaryotic B. Bacterial;...

Transcript of CELLS Two main types of cells are and _. A. Prokaryotic; eukaryotic B. Bacterial;...