[L2] - Cell: The Basic Unit of Life

Prokaryotes

• The simplest organism.

Capsule

• Gel-like coating outside the cell wall

Nucleoid

• Location of the bacterial chromosome

• Where the DNA is located in a single circular.

Ribosome

• Site of protein synthesis

• Many proteins specified by bacterial DNA are synthesized on tiny structures.

Plasma Membrane

• Sheet that surrounds the cytoplasm and regulates entrance and exit of molecules.

Cell wall

• Structure that provides support and shapes the cell

Cytoplasm

• Semi-fluid solution surrounded by the plasma membrane; contains nucleoid and ribosomes.

Flagellum

• Rotating filament that propels the cell

• Protruding from the surface of a cell that are used in locomotion.

Peptidoglycan

• The cell wall is composed of (blank) which consists of a carbohydrate matrix that is cross-linked by short polypeptide units.

Compartmentalization

• What is the hallmark of the eukaryotic cell?

Endomembrane System

• This is achieved through a combination of an (blank) that weaves through the cell interior and by numerous organelles.

Nucleus

• The largest and most easily seen organelle within a eukaryotic cell.

Nucleolus

• Many nuclei exhibit a dark-staining zone called (blank), which is a region where intensive synthesis of ribosomal RNA is taking place.

Chromatin

• DNA is divided into multi linear chromosomes.

• These are organized with proteins into a complex structure.

• Nuclear Pores

• Nuclear Envelope

• Nucleolus

• Chromatin

• Nucleoplasm

• Nuclear Lamina

• Nuclear Basket

• Inner Membrane

• Outer Membrane

• Cytoplasmic Filaments

• Nuclear pore

• Enumerate the parts of nuclei.

Ribosomal RNA

• Each ribosome is composed of two subunits and is composed of what?

Universal Organelles

• Ribosomes can be thought of (blank) because they are found in all cell types from all three domains of life.

Endoplasmic Reticulum

• The largest of the internal membranes is called.

Rough Endoplasmic Reticulum

• It appears to be composed primarily of flattened sacs, the surfaces of which are bumpy with ribosomes.

• Proteins synthesized are destined to be exported from the cell.

Smooth Endoplasmic Reticulum

• It is a region of the ER with relatively few bound of ribosomes.

• It store intracellular Ca²+

• It modify the foreign substances to make them less toxic.

Cisternae

• The individual stacks of membrane are called (blank), and they vary in number within the Golgi body.

Golgi Apparatus

• It functions as collection, packaging, and distribution of molecules synthesized at one location.

• Cis face

• Trans face

• What are the two faces of the Golgi apparatus?

Lysosomes

• They contain high levels of hydrolytic degrading enzymes.

• These enzymes break down old organelles or broken parts of a cell.

Peroxisome

• It contains enzymes involved in the oxidation of fatty acids.

Hydrogen peroxide

• It is produced as a by-product of the activities of oxidative enzymes.

Enzyme Catalase

• It is an enzyme that breaks down hydrogen peroxide into water and oxygen.

Vacuoles

• Plant cells have specialized membrane-boundef structures and it's called?

Tonoplast

• It contains channels for water that are used to help the cell maintain its tonicity, or osmotic balance.

Mitochondria

• It metabolize sugar to generate ATP

• They are typically tubular or sausage-shaped organelles about the size of bacteria that are found in all types of eukaryotic cells.

• Known as power house of the cell.

• Inner membrane

• Outer membrane

Mitochondria are bounded by two membranes.

Cristae

• The inner membrane with numerous contiguous layers are what?

Matrix

• It is lying inside the inner membrane

Intermembrane space

• It is lying between the two mitochondrial membranes.

Chloroplasts

• Uses light to generate ATP and sugars.

• It contains the photosynthetic pigment chlorophyll that gives most plants their green color.

Granum

• Chloroplasts have closed compartments of stacked membranes called (blank), which lie inside the inner membrane.

Thylakoid disk

• Each granum may contain from a few to several dozen disk-shaped structures called (blank).

Stroma

• It is a fluid matrix that surrounds the thylakoid.

Plastids

• Collectively term for chloroplasts, leucoplasts, and amyloplasts.

Actin Filaments

• Long fibers about 7 nm in diameter.

• Each filament is composed of two protein chains loosely twined together like two strands of pearls.

Microtubules

• The largest of the cytoskeletal elements, are hollow tubes about 25 nm in diameter, each composed of a ring of 13 protein protofilaments.

Intermediate filaments

• The most durable element of the cytoskeleton in animal cells.

• A system of tough, fibrous protein molecules twined together in an overlapping arrangement.

Centrioles

• These are barrel-shaped organelles found in the cells of animals and most protists.

Centrosome

• It is the region that surrounds the pair in almost all animal cells.

Cilia

• These are short cellular projections that are often organized in rows.

Primary walls

• These are laid down when the cell is still growing.

Middle lamella

• Between the walls of adjacent cells a sticky substance glues the cells together.

Secondary walls

• They are deposited inside the primary walls of fully expanded cells