BIOL120 - Exam 3

Nuclear Lamina

Stiffens the membrane’s structure and maintains its shape – Provides attachment points for each chromosome

Nuclear Pores

Doors in and out of the nucleus

How are Molecules imported into the nucleus

Messenger RNAs and ribosomes are synthesized in the nucleus and exported to the cytoplasm

What allows things to enter the nucleus

Nuclear Localization Signal

Endomembrane System

Smooth and Rough ER, Golgi Apparatus

Secretory Pathway Hypothesis

proposes that proteins intended for secretion from the cell are synthesized and processed in a highly prescribed set of steps

Signal Hypothesis

predicts that proteins bound for the endomembrane system have a “zip code” that directs the growing polypeptide to the ER.

Where new cisternae form

Cis Face

Where old cisternae break off

Trans Face

How are products shipped from the Golgi

Each protein that comes out of the Golgi apparatus has a molecular tag that places it in a particular type of transport vesicle

Exocytosis

Some proteins are sent to the cell surface in vesicles that fuse with the plasma membrane, releasing their contents to the exterior of the cell

Three types of cytoskeleton elements

Actin filaments (microfilaments) – Intermediate filaments – Microtubules

Smallest Cytoskeleton Element

Actin Fillament

Actin Filaments are grouped together into…

long bundles or dense networks

Actin Filaments can be involved in movement with …

The motor protein myosin

Actin Myosin interactions can cause..

Cell Crawling, Cytokinesis, and Cytoplasmic Streaming

Intermediate Filaments are determined by…

Size

Intermediate Filaments provide…

Structural Support

Why do intermediate filaments form a flexible skeleton

Shape the cell surface and hold the nucleus in place

Microtubules are made of..

tublin dimers

Microtubules are Polar (T/F)

True

What is the microtubule organizing center

centrosome

What are bundles of microtubules in the centrosome called?

centrioles

Microtubiles Function

Stability and movement

What do microtubules require for vesicle transport?

ATP and Kinesin

Flagella Structure

Long Hairlike projections from the cells surface

Flagella Function

Move the cell

Bacterial Flagella are made of..

Flagellin

Bacterial Flagella move…

rotate like a propellor

Eukaryotic Flagella are made of..

Microtubules

Eukaryotic Flagella move…

by weaving back and forth

Cilla are closely related to…

eukaryotic flagella

Cells generally have how many flagella?

one or two

Axoneme of Cilla and Flagella

is a complex “9+2” arrangement

Where does anemone attach to the cell?

Basal Body

Where does the motor protien dynein form?

in the arms between doublets

What is the function of the Extracellular Layer?

fiber composite

Function of the Extracellular Layer

protect against tension and compression

When new plant cells form they secrete a fiber composite called…

primary cell wall

What is the primary cell wall made of

long strands of cellulose bundled into microfibrils and filled with hydrophilic gelatinous polyscarrarides

The amount and composition of the ECM varies based on..

cell type

The most common ECM protein fiber is..

collagen

ECM function

Structural Support and helps cells stick together

The ECM is strengthened by connections to…

Transmembrane protiens

Actin protein filaments in the cytoskeleton bind to

integrin proteins

Integrins bind to ECM protiens such as…

fibronectins

physical connections between cells are the basis of

multicellularity

Groups of similar cells performing similar functions comprise

tissues

Cell-Cell Attachments

Structures that hold cells together vary among multicellular organisims

The extracellular space between adjacent plant cells comprise … layers

three

Plant cells are glued together by the…

middle lamella

The middle lamella is comprised of..

Gelatinous pectins

Epithetical tissue is comprised of…

sheets of cells that cover organs and line body cavities

Tight Junctions are comprised of..

specialized proteins in the plasma membrane of adjacent animal cells

Tight junctions are usually found…

between cells in tissues that form a barrier

Tight Junctions are..

Dynamic and Variable

Desmosomes are made of..

proteins that link the cytoskeleton of adjacent cells

Desmosomes are common in…

epithelial and muscle tissues

Experiments using adult sponges demonstrated…

selective adhesion

Cadherins are the adhesion proteins in..

desmosomes

Direct connections between cells in the same tissue allow..

Cells to communicate and work together in a coordinated fashion

Plant cells are connected by…

plasmodesmata, gaps in the cell wall, and smooth er

In most animal tissues, gap junctions connect adjacent cells by..

forming channels that allow the flow of small molecules between cells

A Hormone is..

an information carrying molecule that is secreted from a cell

Lipid Soluble hormones usually diffuse…

across the plasma membrane into their target cell’s cytoplasm

Lipid insoluble hormones are…

large or hydrophilic and do not cross the plasma membrane and instead bind to a receptor on the plasma membrane

Hormones and other cell-cell signals bind to..

signal receptors

Identical receptors in diverse cells and tissues allow..

long distance signals

Receptors can be blocked (T/F)

True

Lipid-soluble steroid hormones bind to receptors…

inside the cell and trigger direct changes

a signal transduction pathway converts…

the extracellular hormone signal into an intercellular signal

Signal transduction occurs at the..

plasma membrane

Amplification occurs…

inside the plasma membrane

G Proteins trigger..

the production of an intracellular messenger

Enzyme linked receptors trigger

the activation of a series of proteins inside the cell

G Proteins are

intracellular peripheral membrane proteins'

G proteins link the receipt of an extracellular signal to

the production of an intracellular signal

G proteins are activated when they bind to

to GTP

G proteins are deactivated when

they hydrolyze GTP to GDP

Second messengers are

small molecules that diffuse rapidly through the cell

Many second messengers work by activating

protein kinases to add a phosphate group

The best know group of enzyme linked receptors is

receptor tyrosine kinases (RTK)

Results of signal transduction events

easily transmitted extracellular message to intracellular message and the original message is amplified

Cross talk integrates..

the diverse signal that a cell receives

Cell-Cell communication in bacteria is called

quorum sensing

Bacteria releases _____ when their numbers reach a certain threshold

specific signaling molecules

Where does cellular respiration occur

Cytoplasm and Mitochondria

Aerobic Respiration

Oxygen present

Anaerobic Respiration

Lack of Oxygen

First step of cellular respiration

Glycolysis

Gylco:

Sugar, Glucose

Lysis:

Breakdown

Anaerobic Respiration in yeast cells

alcoholic fermentation

Anaerobic Respiration in Muscle Cells

Lactic Acid Fermentation

What type of respiration is the Krebs Cycle

Aerobics

Phosphorylation causes proteins to

change shape and move

Phosphorylation drives what cellular processes

Transport of proteins, movement of flagella/cilia and ion pumps

protein phosphorylation leads to

the exergonic phosphorylation reaction coupled with an endergonic reaction

Redox reactions are

chemical reactions that involve an electron transfer

when an atom/molecule gains an electron it is

reduced