Chapter 6 study notes

Scanning electron microscopes (SEMs)

focus a beam of electrons onto the surface of a specimen, providing images that look 3-D

Transmission Electron Microscope (TEM)

focus a beam of electrons through a specimen; used mainly to study the internal structure of cells

Lysosome

membranous sac of hydrolytic enzymes that can digest macromolecules

Why are cells so small? Explain the relationship of surface area to volume.

smaller cells have more surface area across which to pass oxygen, nutrients and waste materials. The bigger the surface area the better but the surface area of a cell decreases as it increases in volume. So cells stay the small size they are to retain the greatest surface area possible in relation to their volume

Food vacuoles

Are formed by phagocytosis

What are the functions of the rough ER?

- Has bound ribosomes, which secrete glycoproteins (proteins covalently bonded to carbohydrates - Distributes transport vesicles, secretory proteins surrounded by membranes - Is a membrane factory for the cell

What are functions of the smooth ER?

- Synthesizes lipids - Metabolizes carbohydrates - Detoxifies drugs and poisons - Stores calcium ions

What are the components of the endomembrane system?

-Nuclear envelope -Endoplasmic reticulum -Golgi apparatus -Lysosomes -Vacuoles -Plasma membrane these components are either continuous or connected via transfer by vesicles

What is a lysosome? What do they contains? and what is the pH?

A lysosome is a membranous sac of hydraulic enzymes. It digests macromolecules and they contain enzymes that function in the acidic environment of the cell. They have a pH of about 4.5

Which structure is part of the endomembrane system? a. mitochondrion b. chloroplast c. golgi apparatus d. centrosome

B. Golgi apparatus

What 2 domains consist of prokaryotic cells?

Bacteria and Archaea

What matches an organelle with its function?

Central vacuole with storage

What does Golgi apparatus consist of and what are the functions

Consists of flattened membranous sacs called cisternae and the functions are it modifies products of the ER, manufactures certain macromolecules, sorts and packages materials into transport vesicles

What are the characteristics of a eukaryotic cell?

DNA in a nucleus that is bounded by a membranous nuclear envelope, membrane-bound organelles, cytoplasm between the plasma membrane and nucleus

A cell has formed a food vacuole as it ingested a food particle. What is associated with the breakdown of that food particle?

Digestion of the food particle occurs in a vesicle enclosed by a membrane that separates the digestion from the cytoplasm

What 2 areas do ribosomes carry out protein synthesis?

In the cytosol (free ribosomes) and on the outside of the endoplasmic reticulum / the nuclear envelope (bound ribosomes)

Vacuoles

Large vesicles derived from the ER and Golgi Apparatus and can perform a variety of functions in different kinds of cells

What is something that is NOT associated with the cytoskeleton in eukaryotic cells?

Movement of RNA molecules from the nucleus to the cytoplasm

What are the characterizations of a prokaryotic cell?

No nucleus, DNA in a nucleoid, no membrane-bound organelles, cytoplasm, and ribosomes

Describe the nuclear envelope. How many layers is it? What connects the layers?

Nuclear envelope: double membrane enclosing the nucleus; perforated by pores and continuous with ER - Has 2 layers made up of phospholipids; tail is hydrophobic and head is hydrophilic

What structures are common in both plant and animal cells?

Nucleus, cytoplasm, mitochondrion, and cell membrane

What all consists of eukaryotic cells?

Protists, fungi, animals and plants

What is the function of ribosomes? What are their 2 components?

Ribosomes are cellular components that carry out protein synthesis and are made up/composed of ribosomal RNA and proteins

What are 2 types of electron microscopes (EMs) and what are they used for?

Scanning electron microscopes (SEMs) and Transmission electron microscopes (TEMs) and they are used to study subcellular structures

A major difference between prokaryotic and eukaryotic cells is the location of their DNA. Describe the difference

The DNA of eukaryotes is in a bound nucleus and the DNA present in prokaryotes is the nucleotide

What is the process with hydrolytic enzymes and lysomal membranes

They are both made by rough ER and then transferred to the golgi apparatus for further processing

Nuclear matrix

a framework of protein fibers extending throughout the nuclear interior (the inside)

plasma membrane

a selective barrier that allows sufficient passage of oxygen, nutrients, and waste to service the volume of every cell

Which of the following is present in a prokaryotic cell? a. nuclear envelope b. ribosome c. mitochondrion d. chloroplast

b. ribosome

Which one of the following statements about the endomembrane system is correct? a. Mitochondria function in the modification and sorting of lipids and proteins. b. The endoplasmic reticulum is continuous with the plasma membrane. c. Proteins that will be secreted from the cell are likely to be found in closed spaces bounded by membranes of the endomembrane system. d. Most of the phospholipids of the endomembrane system are synthesized in the mitochondria. e. Ribosomes move lipids and proteins among the different organelles of the endomembrane system.

c. Proteins that will be secreted from the cell are likely to be found in closed spaces bounded by membranes of the endomembrane system.

Ribosomes

complexes made of ribosomal RNA and protein

Which of the following clues would tell you if a cell is prokaryotic or eukaryotic? a. the presence or absence of ribosomes b. whether or not the cell contains DNA c. whether or not the cell carries out cellular metabolism d. whether or not the cell is generally partitioned by internal membranes e. the presence of absence of a rigid cell wall

d. whether or not the cell is generally partitioned by internal membranes

What is nuclear lamina

like cytoskeleton a netlike array of protein filaments that maintains the shape of the nucleus by supporting the nuclear envelope

Autophagy

lysosome fuses with the food vacuole and digests the molecules, then lysosome uses enzymes to recycle the cell's own organelles and macromolecules

Basic features of all cells

plasma membrane, cytosol, chromosomes (carry genes), ribosomes (makes proteins)

Cell fractionation

takes cells apart and separates the major organelles from one another and enables scientists to determine the functions of organelles