General Microbiology Ch5 Test 1 Content

Dr. Pipkins General Micro WCU

What structures must be present in a eukaryotic cell?

Cell Membrane

Mitochondria, Golgi Apparatus, Endoplasmic Reticulum

Cytoplasmic Matrix

Ribosomes

Nucleus (Nucleolus, Nuclear envelope, Nucleoplasm)

Cytoskeleton (Microtubules/centrioles, Intermediate filaments, Microfilaments)

Glycocalyx

Slimy cell covering made of polysaccharides

Outermost boundary of most eukaryotic cells

Similar to prokaryotic slime layer

Functions in protection, adherence, biofilm formation, and cell-cell communication

Microvilli

Finger-like projects that aid in nutrient absorption

Cell Membrane

Phospholipid bilayer studded with proteins that encases the cytoplasm

Serves as selectively permeable barrier and functions in signal transduction

Cell Wall

Polysaccharide layer surrounding the cell membrane

Provides rigidity and structure

Found in plants, fungi, and algae

Includes a variety of polysaccharides and proteins

NO peptidoglycan

Nucleus

Control center of the cell

Nuclear Envelope

Porous membrane separating the nucleus from the cytoplasm

Nucleoplasm

Gelatinous matrix within the nucleus containing chromatin

Nucleolus

Site of rRNA synthesis and ribosome construction

How is DNA stored?

DNA is stored as chromatin in the nucleoplasm until it condenses to form chromosomes during cell division

Rough Endoplasmic Reticulum (RER)

Continuous network of ribosome-studded sacs involved in the synthesis of proteins

Smooth Endoplasmic Reticulum (SER)

Closed tubular network without ribosomes; site of lipid synthesis

What is the size of a eukaryotic ribosome?

80S

Golgi Apparatus

Collects proteins and lipids from the ER, modifies them, and packages them for transport to their final destination

Cellular Assembly Line

rRNA synthesized in nucleolus to make ribosomes (later located on rough ER)

Proteins are synthesized at ribosomes on rough ER; Lipids are synthesized in smooth ER

Smooth/Rough ER bud off transport vesicles full of lipids or proteins that are picked up by the Golgi apparatus

Proteins and Lipids are modified in the Golgi

Golgi pinches off transport vesicles that travel somewhere else inside the cell or are secreted outside of the cell

Lysosomes

Cellular vesicles containing digestive enzymes

Mitochondria

Generates and stores cellular energy in the form of ATP

Has inner membrane folded into cristae

Chloroplast

Organelle found in algae and plants that converts sunlight into chemical energy via photosynthesis

Contains stacks of thylakoids with chlorophyll

What are the parts of the cytoskeleton?

Microfilaments, Intermediate filaments, Microtubules, Centrioles (microtubule-organizing centers)

What do centrioles do in mitosis?

They give rise to spindle fibers that pull apart duplicated chromosomes during mitosis

Eukaryotic Motility Appendages

Cilia and Flagella

Cilia

Short, sheathed cylinders made of microtubules

Many are present on cells (hundreds to thousands)

Function in locomotion and filter feeding (Provide motility by moving in oar-like strokes as a group)

Found in select protozoa

Flagella

Long, sheathes cylinders made of microtubules

Functions in locomotion and sensing the environment (Whips back and forth or grabs a surface and pulls the cell)

Found in some helminths, protozoa, algae, and fungi

Ciliary Locomotion

Power stroke propels cell forward

Recovery stroke returns cell to original position

Filter feeding (Cilia)

Cilia move water/environment towards the cell, consuming smaller organisms/food

Flagellar Locomotion

Whips back and forth and pushes in snake-like pattern

OR

Lashes, grabs the substrate, and pulls

***Eukaryotic flagella do not rotate 360 degrees like prokaryotic flagella