Cell Biology Chapter 6 Review: Intercellular Junctions and ER Functions

A set of vocabulary flashcards covering key concepts from Chapter 6 on Intercellular Junctions and ER Functions.

Plasmodesmata

Junctions found in plant cells that allow for the exchange of materials between cells.

Tight Junctions

Type of intercellular junction that connects cells tightly together, preventing substances from passing between them.

Desmosomes

Intercellular junctions that anchor cells together but allow for some flexibility and space between cells.

Gap Junctions

Junctions that allow direct communication between adjacent cells through cytoplasmic channels.

Extracellular Fluids

Fluids outside cells that may move through intercellular spaces, largely affected by the type of junctions present.

Rough Endoplasmic Reticulum (Rough ER)

A type of endoplasmic reticulum that is involved in protein synthesis due to the presence of ribosomes.

Smooth Endoplasmic Reticulum (Smooth ER)

A type of endoplasmic reticulum primarily involved in the detoxification of drugs and metabolism of lipids.

Intercellular Junctions

Structures that connect cells to one another, facilitating communication and structural integrity.

Cytoplasmic contact

Direct connection between the cytoplasm of adjacent cells, as seen in gap junctions.

Detoxification

The process by which the liver removes toxins from the body, associated with the smooth ER.

Eukaryotic Cells

Have a nucleus, and membrane bound organelles

Prokaryotic Cells

Have a nucleoid region and are only found in bacteria and archaea, lacking membrane bound organelles.

DNA in nucleus contains instructions for..?

Protein synthesis

Where is protein synthesized?

In ribosomes

Endomembrane system

Regulates protein traffic and performs various metabolic functions

Cytoskeleton

Network of fibers that organizes structures and activities within the cell.

Fimbirae

Hair like structures for attachment on Prokaryotic Cells

Plasma membrane on prokaryotic cells

Encloses the cytoplasm

Cytoplasm

Region between the nucleus and plasma membrane

What is the typical size of a eukaryotic cell?

10-100 um in diameter

Where does photosynthesis happen?

In the chloroplasts

What pigment is in chloroplasts?

Chlorophyll

What are the stacks of thykaloids called?

Grana

Endoplasmic reticulum

Network of membranous tubules and sacs

What is the rough ER studded with?

Ribosomes

What processes are the smooth ER involved in?

Lipid synthesis and detoxification processes

What is the nuclear envelope?

Double membrane structure, encloses the nucleus and separates its concets from the cytoplasm

What do pore complexes in the nuclear envelope do?

Regulate entry of proteins, RNAs, and large macromolecules

What is the nuclear lamina

Netlike array of protein filaments

What does the nuclear lamina do?

Supports the nuclear envelope and helps maintain the shape of the nucleus

Nuclear matrix

Framework of protein fibers that helps ORGANIZE GENETIC MATERIAL

Chromatin

DNA-protein complex

How many chromosomes do human cells have?

46

How many chromosomes do sx cells have?

23

What is the nucleolus involved in synthesizing?

Ribosomal RNA (rRNA) and assembling ribosomal subunits from rRNA and proteins

How does the nucleus direct protein synthesis?

By synthesizing messenger RNA (mRNA) from DNA. The mRNA is transported to the cytoplasm via nuclear pores, where ribosomes translate the mRNA into POLYPEPTIDEs.

What are ribosomes made of?

Complexes made of ribosomal RNAs and proteins that carry out protein synthesis

Are ribosomes considered organelles?

No, they are not membrane bound

When cells have high rates of protein synthesis, that means they have…

Large numbers of ribosomes and prominent nucleoli

Other than bound to the rough ER, where else can ribosomes be found?

Free in the cytosol

Can free and bound ribosomes switch roles?

Yes

What do bound ribosomes generally produce proteins for?

For insertion into membranes, packaging within organelles, or secretion from the cell.

Example of a cell that specializes in protein secretion

Pancreatic cells, have lots of bound ribosomes

Nucleoli are compssed of…

RNA and proteins

As cells begin to divide…

Chromosomes condense. They become shorter and thicker.

When chromosomes condense in cell division,

The coiling and supercoiling of DNA around histone proteins gets involved.

What does the endomembrane system in eukaryotic cells include?

Nuclear envelope, endoplasmic reticulum, Golgi apparatus, lysosomes, vesicles, vacuoles, and plasma membrane.

What is the endomembrane system responsible for?

Protein synthesis, transport, lipid metabolism and movement, and detoxification.

What is the ER continuous with?

The nuclear envelope

The smooth ER lacks….

Ribosomes

The smooth ER stores…

Calcium ions

What does the Rough ER function as

The membrane factory, adding membrane proteins and phospholipids to its own membrane.

What does the golgi apparatus function as?

The warehouse for products sent from the ER, such as proteins.

Golgi apparatus

Consists of flattened membranous sacs called cisternae.

The cisternae are

Stacked and separated from the cytosol.

What do vesicles do?

Transport materials between the ER, Golgi, and other cellular structures.

How do transport vesicles ensure they deliver their contents to the correct target organelle or plasma membrane?

They possess external molecules on their surface that RECOGNIZE and BIND to specific docking sites on the target membrane.

Lysosomes are..

Membranous sacs containing hydrolytic enzymes used to digest macromolecules in eukaryotic cells.

What does the 3D shape of lysosomal membrane proteins do?

Protect them from enzymatic attack

Phagocytosis

Process where specialized immune cells ear and destroy dead cells.

Autophagy

Process where lysosomes recycle cells own organic material

Vacuoles

Large vesicles derived from the endoplasmic reticulum and Golgi apparatus

Where are Hydrolytic vacuoles found?

In plants and fungi. They carry out enzymatic HYDROLYSIS(BREAKDOWN W WATER)

How do central vacuoles in mature plant cells play a large role?

By absorbing water, which allows the cell to enlarge with minimal new cytoplasm.

What does the number of mitochondria in a cell correlate to?

The cells metabolic activity

What are the components of the mitochondrial matrix?

Enzymes, mitochondrial DNA, and ribosomes

What happens when the cristae increases the inner membrane surfaces area?

It enhances cellular respiration efficiency

What is the chloroplast enclosed by?

An envelope consisting of two membranes with a narrow inter-membrane space.

What is the fluid outside of thykaloids in chloroplasts?

Stroma

What are peroxisomes

Specialized metabolic compartments bounded by a single membrane.

What organelle contains enzymes that remove hydrogen atoms from substrates and transfer them to oxygen and produces hydrogen peroxide as a by product?

Peroxisomes