Biology, Chapters 6, 7.1

Front 1

What is an ORGANELLE?

Back 1

Subcellular structure find in the CYTOSOL of the the cell.

Front 2

What are the two types of ELECTRON MICROSCOPE?

Back 2

1. SCANNING ELECTRON MICROSCOPE (SEM) - used for the detailed study of the surface of a specimen.
2. TRANSMISSION ELECTRON MICROSCOPE (TEM) - used mainly for the study of the internal structure of the cell.

Front 3

What is CYTOLOGY?

Back 3

The study of a cell's structure

Front 4

What is CELL FRACTIONATION?

Back 4

To take a cell apart and seperate the major organelles from one another. (Usually done with a centrifuge.)

Front 5

What are the basic features common to all cells?

Back 5

- All bounded by a membrane (called a PLASMA MEMBRANE)
- CYTOSOL (semifluid substance within the membrane)
- All cells have CHROMOSOMES (carrying genes in the form of DNA)
- RIBOSOMES - tiny organelles that make proteins according to instructions from the genes.

Front 6

What is the major difference between PROKARYOTIC and EUROKARYOTIC cells?

Back 6

Chromosomes of a eukaryotic cell are located in a membrane-enclosed organelle called the NUCLEUS.

Front 7

Where is DNA found in a PROKARYOTIC cell?

Back 7

Concentrated in a region called the NUCLEOID (though it is not enclosed by a membrane.

Front 8

What is the NUCLEAR LAMINA?

Back 8

A netlike array of protein filaments that maintains the shape of the nucleus by mechanically supporting the nuclear envelope.

Front 9

Where are CHROMOSOMES found?

Back 9

In the nucleus.
- Chromosomes carry genetic information.
- Chromosomes are made up of material called CHROMATIN (a complex of proteins and DNA).

Front 10

What is the NUCLEOLUS?

Back 10

A prominent structure within the non-dividing nucleus.
- Here a special type of RNA called ribosomal RNA (rRNA) is synthesized from instructions in the DNA.
- Proteins imported from the cytoplasm are assembled with the rRNA into large nd small ribosomal subunits in the nucleolus.

Front 11

What is a RIBOSOME?

Back 11

The organelles that carry out protein synthesis.
- Free Ribosomes float free in the cytosol
- Bound Ribosomes are attached to the outside of the Endoplasmic Reticulum.

Front 12

What is the difference between FREE and BOUND Ribosomes?

Back 12

Free - Most proteins made on free ribosomes function within the cytosol (eg. enzymes that catalyse the first steps of sugar breakdown.)
- Bound: generally make proteins that are desined either for insertion into membranes, for packaging within certain organelles such as lysosomes or for export from the cell (secretion).

Front 13

What is the ENDOMEMBRANE SYSTEM?

Back 13

Different membranes that make up the Eukaryotic cell.

Front 14

What components of a cell are included in the ENDOMEMBRANE SYSTEM?

Back 14

Nuclear envelope; edoplasmic reticulum; Golgi apparatus; lysosomes, various kinds of vacuoles and the plasma membrane.

Front 15

What is the ENDOPLASMIC RETICULUM?

Back 15

An extensive network of membranes that seperates the internal compartment of the ER, caled the ER lumen or cisternal space, from the cytosol.

Front 16

What composes the ENDOPLASMIC RETICULUM?

Back 16

SMOOTH ER: so named because it's outer surface lacks ribosomes
ROUGH ER: has ribosomes that stud the outer surface of the membrane.

Front 17

What is the role of the SMOOTH ER?

Back 17

Important to the synthesis of lipids, including oils, phospholipids and steroids.
- Enzymes help detoxify drugs and poisons, especially in the liver cells.
- Stores calcium ions

Front 18

What is the role of the ROUGH ER?

Back 18

Protein secretion produced by ribsomes attached to the rough ER.
- Also the membrane factory for the cell

Front 19

What is the GOLGI APPARATUS?

Back 19

We can think of it as the center of manfacturing, warehousing, sorting and shipping.
- Products of the ER are odified and stored and then sent to other destinations.
- Especialy extensive in cells specialized for secretion.

Front 20

What is a GLYCOPROTEIN?

Back 20

A secretory proteins. (Have carbohydrates covalently bonded to them.)
- Found in the ER.

Front 21

What composes the ENDOPLASMIC RETICULUM?

Back 21

SMOOTH ER: so named because it's outer surface lacks ribosomes
ROUGH ER: has ribosomes that stud the outer surface of the membrane.

Front 22

What is the role of the SMOOTH ER?

Back 22

Important to the synthesis of lipids, including oils, phospholipids and steroids.
- Enzymes help detoxify drugs and poisons, especially in the liver cells.
- Stores calcium ions

Front 23

What is the role of the ROUGH ER?

Back 23

Protein secretion produced by ribsomes attached to the rough ER.
- Also the membrane factory for the cell

Front 24

What is the GOLGI APPARATUS?

Back 24

We can think of it as the center of manfacturing, warehousing, sorting and shipping.
- Products of the ER are odified and stored and then sent to other destinations.
- Especialy extensive in cells specialized for secretion.

Front 25

What is a GLYCOPROTEIN?

Back 25

A secretory proteins. (Have carbohydrates covalently bonded to them.)
- Found in the ER.

Front 26

Describe the path of a product from the ER to the Golgi appartus.

Back 26

Product protein:
- arrives on the CIS face (recieving end)
- usual modified as it travels to the TRANS end (shipping side)
- proteins are usually transported to the plasma membrane for secretion.

Front 27

What is a LYSOSOME?

Back 27

A membranous sac of hydrolytic enzymes that an animal cell uses to digest all kinds of macromolecules. (Carry out intracellular digestion.)
- lysomal enzymes work best in the acidic environment found in lysosomes.

Front 28

What is PHAGOCYTOSIS?

Back 28

The process of whereby amoebas and other protists eat by engulfing smaller organisms or other food particles.

Front 29

What is AUTOPHAGY?

Back 29

The process by which lysosomes use their hydrolytic enzymes to reyclce the cell's own organic material.

Front 30

What is a VACUOLE?

Back 30

Membrane sac that plays a role in intracellular disgestion and the release of cellular waste products.
- In the plant cell, the central vacuoleis usually the largest compartment.

Front 31

What is a TONOPLAST?

Back 31

The membrane that encloses the large, central vacuole in a plant cell.

Front 32

How important is the VACUOLE to a plant cell?

Back 32

Extremely. Plant cells enlarge as their vacuoles absorb water, enabling the cell to become larger with a minimal investment in the new cytoplasm.

Front 33

What is a MITOCHONDRIA?

Back 33

- Sites of cellular respiration
- Sites of the metabolic process that generates ATP by extracting energy from sugar, fats and other fuels with the help of oxygen.

Front 34

What are CHLOROPLASTS?

Back 34

Found only in plants and algae, are the sites of photosynthesis.
- contain the green pigment chlorophyll, along with enzymes and other molecules that function in the photosynthetic production of sugar.

Front 35

Are MITOCHONDRIA and CHLOROPLASTS part of the endomembrane system?

Back 35

In contrast to the organelles of the endomembrane system, these organelles have at least two membranes separating the innermost space from the cytosol.
- additionally, the contain DNA that prgorams the synthesis of the proteins made onthe organelle's own ribsomes

Front 36

What is a PLASTID?

Back 36

e.g. The Chloroplast is a specializd member of a family of closely related plant organelles.

Front 37

What is a PEROXISOME?

Back 37

A specialized metabolic compartment bounded by a single membrane.
- they contain enyzmes that transfer H from various substrates to O, producing Hydrogen peroxide.

Front 38

What is the CYTOSKELETON?

Back 38

Network of fibers extending throughout the cytoplasm.
- Gives mechanical support to the cell and helps maintain its shape
- Plays a major role in organizing the structures ad activities of the cell
- Composed of microtubules microfilaments and intermediate filaments.
- Can be disassembled and reassembled to change the shape of the cell

Front 39

Is the CYTOSKELETON more important in plant or animal cells?

Back 39

Animal cells b/c they lack walls.

Front 40

What is CELL MOTILITY?

Back 40

Encompasses bot changes in cell location and more limited movements of parts of the cell.
- Requires the interaction of the cytoskeleton with proteins called MOTOR PROTEINS

Front 41

What is the function of the MICROTUBULES?

Back 41

- Thickest component of the cytoskeleton
- They shape and support the cell
- Serve as tracks along which organelles equipped with motor proteins can move
- Responsible for the separation of chromosomes during cell division
- Act as compression-resisting girders of the cytoskeleton
- provide support to the motion of CILIA and FLAGELLA

Front 42

What is the CENTROSOME?

Back 42

A region often locatd near the nucleus that is considered to be a "microtubule-organizing center"

Front 43

What are CENTRIOLES?

Back 43

Found in the centrosome of the animal cell, each is composed of nine sets of triplet microtubules arranged in a ring
- Before a cell divides, centrioles replicate

Front 44

Do plant cells have CENTROSOMES/CENTRIOLES?

Back 44

- Both have centrosomes
- Plant cells do not have centrioles

Front 45

What is a DYNEIN?

Back 45

Dynein arms are responsible for he bending movements of cilia and flagella.
- Motor protein
- Performs a complex cycle of movements caused by changes in the conformation of the protein with ATP providing the energy for these changes. (Like a cat walking along along the branch of a tree.)

Front 46

Provide info on a MICROFILAMENT.

Back 46

- also called ACTIN filaments
- appear to be present in all eukaryotic cells
- role is to bear tension (pulling forces) between the microtubules
- form a 3-D network inside the plasma membrane that helps support the cells shape
- known for their role in cell molility

Front 47

What is a PSEUDOPODIA?

Back 47

Assist in the movement of amoeba

Front 48

What is MYOSIN?

Back 48

Motor protein that help with the movement of microfilaments

Front 49

What are INTERMEDIATE FILAMENTS?

Back 49

- Also specialized for bearing tension
- Larger than microfilament but smaller than microtubules
- more permanent fixtures in cells than microtubules or microfilaments
- they assist with the anchoring of the nucleus

Front 50

What is PLASMODESMATA?

Back 50

Perferations found in the walls of plant cells through which cytosol passes to connect to the chemical environment of adjacent cells.

Front 51

What is SELECTIVE PERMEABILITY?

Back 51

The plasma membrane allows some membranes to cross it more easily than others.

Front 52

What are the staple ingredients of the plama membrane?

Back 52

- Lipids and proteins
- To a lesser extent, carbohydrates

Front 53

What is the most abundant lipid in the plasma membrane?

Back 53

Phosopholipids

Front 54

What is AMPHIPATHIC?

Back 54

A phosopholipid is amphipatic in that it has both hydrophilic and hydrophobic regions.

Front 55

What is an INTEGRAL PROTEIN?

Back 55

A protein that pentrates th hydrophobic core of the lipid bilayer.
- Many can be transmembrane prtoein, which completely span the membane

Front 56

What is a GLYCOLIPID?

Back 56

A carbohydrate that is covalently bonded to lipids (e.g. to phospholipids in the plasma membrane layer)