Chapter 4 BIO1511

What is the diameter of most cells?

less than 50 micrometers

Most cells are microscopic except...

vertebrate eggs that can be seen with the naked eye

Where is DNA located?

Nucleoid (not segregated) or nucleus (with a nuclear envelope)

Prokaryotic cells

*Simplest organisms: have a wall and membrane covering the cytoplasm
*Lack membrane bound nucleus
*Has ribosomes

In prokaryotic cells where is the DNA located?

DNA is located in the nucleoid

What influences the cell wall shape in prokaryotic cells?

Cytoskeleton

What are BMCs in eukaryotic organelles?

functional but not structural analogs

Prokaryotes possess molecules related to _____ and _____ that influence the shape of the cell wall.

actin and tubulin

Where is the nucleoid visible in prokaryotic structure?

the nucleoid is visible in dense central region segregated from the cytoplasm

Bacterial cell walls

Composed if peptidoglycan, a sugar polymer (not necessarily glucose) crosslinked by short polypeptides units

What cell walls are different in bacterial cell walls?

cell walls of plants, fungi, and most protist are different

What are the properties of BCW?

protects the cell, maintains its shape, and prevent excessive uptake or loss of water

What does the susceptibility of bacteria to antibiotics depend on?

often depends on the structure of their cell walls

Glyoxysome

for fat to sugar conversion through glyoxylate cycle

Nucleiolus

region where ribosomal RNA synthesis takes place

What is the outer layer continues with? Nuclear envelope

cytoplasmic endoplasmic reticulum

How is DNA divided in eukaryotes?

multiple linear chromosomes

Chromatin

chromosomes plus protein

Septate or tight junctions

connect the plasma membranes of adjacent cells in a protective sheet preventing leakage

How do proteins give cell identity?

cells make contact, "read" each other, and react

Integrin proteins

attached to microfilaments (Actin) and intermediate filaments of cytoskeleton

What does connectivity allow the ECM to do?

Influence cell behavior such as gene expression and migration patters

How are eukaryotic cell walls distinct from prokaryotic cell walls?

chemically and structurally

What is the eukaryotic flagella and cilia made up of?

9 microtubules pairs surrounding 2 central microtubules

Cilia

Serve to move over the tissue surface, move air waves, etc.

Where are centrioles found?

in most animal cells and most protist

Microtubules organizing centers

can nucleate the assembly of microtubules

Centrosome

the area surrounding the pair of centrioles

What is the centrosomes responsible for?

For organizing of microtubules during cell division

Actin

2 proteins twisted filaments involved in cellular movements

Osmotic pressure

the force required to stop that flow of water

Peroxisomes

are small organelles classified as microbodies that bud off the ER

How are lysosomes activated?

by fusing with either a food vesical introduced by phagocytosis or worn-out organelle

What does low pH do in lysosomes?

activates the hydrolytic enzymes into action

Gogli Apparatus

sorting of proteins and other functions

Where are proteins and lipids received?

in the cis face

What can SER also preform?

modification of foreign substances for detoxification.