Chapter 4 Cellular structure and function

what are the 3 basic parts of a cell

plasma membrane, cytoplasm, and nucleus

what are the 4 functions of the cell membrane

barrier to protect cell, facilitate transport of materials in & out of cell, establish and electrochemical gradient, has receptors to signal/communicate with other cells

What component of the erythrocyte is most responsible for its cytoskeleton and cellular integrity?

cytoskeletal protein

What cellular component of the erythrocyte is its control center?

nucleus

what is the difference between heterochromatin and euchromatin?

heterochromatin - stains dark, clumped, and is genetically INACTIVE

euchromatin - stains pale blue, and is genetically ACTIVE

How does the genetically active portion of the nuclear chromatin look when stained with Wright stain?

Diffuse, uncondensed and pale blue

What cellular component “directs traffic” for smooth functioning?

golgi apparatus

If the cytoplasm of a cell is very basophilic or dark blue when stained with Wright stain, it contains:

large number of ribosomes

Protein synthesis occurs in what part of a cell?

ribosomes

What cellular component is responsible for energy production and metabolic processes?

mitochondria

Lysosomes are found in the cytoplasm of many cells and contain:

hydrolytic enzymes

What cellular structures appear as granules with Wright stain?

lysosomes

The nucleolus of a cell is composed of:

RNA

Where are surface markers that help in cell identification found?

cell membrane

A cell that is actively synthesizing protein has:

more nucleoli

If the lysosomal membrane ruptures, what is the consequence to the cell?

damage to internal cell structures

After birth, where does hematopoiesis predominantly occur?

bone marrow

Erythropoietin is a growth factor affecting erythroid progenitors and is produced by what organ?

kidney

what do microfilaments do

located near the nucleus, they assist in cell division & provide cytoskeletal support

what do microtubules do

they are involved in cell motility and also form the mitotic spindle fibers during mitosis and are the main component of centrioles

what are the methods of passive transport

simple diffusion - molecules move with their concentration gradient

facilitated diffusion - molecules move via protein channels

osmosis - diffusion of water based on solute concentration

what are some methods of active transport

primary active transport - transport pumps, channels, and ATPases move ions against gradient

secondary active transport - 1 molecule transported against gradient, 1 molecule transported along gradient

vesicular transport - molecules transported in vesicles

what are the stages of the cell cycle

G₁ (gap 1), S (DNA synthesis), G₂ (gap 2), M (mitosis)

what are the 5 major checkpoints in the cell cycle

1. restriction point in G₁ (ensures conditions are favorable for cell replications)

2. G₁ DNA damage check

3. S-phase DNA damage and completion of replication

4. G₂ damage DNA checkpoint (check for damaged or unduplicated DNA)

5. Metaphase checkpoint (check for chromosome attachment to mitotic spindle)

In what stage of the cell cycle does DNA replication occur?

S

what is the difference between apoptosis and necrosis

necrosis - cell death via external damage like trauma or toxins

apoptosis - programmed cell death because of aged cell or abnormality in cell

What morphologic characteristic is representative of apoptosis?

cell shrinkage

What morphologic characteristics are representative of necrosis?

cell swelling, inflammation, and cell lysis

what are the 3 components of the nucleus

• nucleoli

• chromatin

• nuclear envelope

what cells are involved in the hematopoietic microenvironment

hematopoietic stem cells (HSCs), stromal cells, and progenitor cells