Cells and Tissues (Q1,P2)

Question 1

Cells

Answer 1

the smallest living units in our bodies

Question 2

Organelles

Answer 2

little organs” – carry on essential functions of cells

Question 3

Enzymes

Answer 3

direct chemical reactions in cells

Question 4

Metabolism

Answer 4

• the sum of all chemical reactions in the cell
• two types: Anabolic reactions & Catabolic reactions

Question 5

Plasma Membrane

Answer 5

• defines the extent of the cell
• has a phospholipid bilayer
• Provides barrier against substances outside the cell
• Some plasma membranes act as receptors
• Determines which substances enter or leave the cell (semipermeable)

Question 6

Nervous Tissue

Answer 6

• Main components of the brain, spinal cord, and nerves
• Contains two types of cells: neurons & Supporting cells (neuroglial cells)

Question 7

Neurons

Answer 7

Conduct electrical impulses

Question 8

Supporting Cells/Neuroglial Cells

Answer 8

nonconducting cells

Question 9

What are the three types of muscle tissue?

Answer 9

Skeletal muscle tissue
cardiac muscle tissue
smooth muscle tissue

Question 10

Skeletal muscle tissue

Answer 10

striations; voluntary movement; long, cylindrical cells (fibers)

Question 11

cardiac muscle tissue

Answer 11

striations; involuntary movement; occurs in walls of heart (myocardium)

Question 12

Smooth muscle tissue

Answer 12

lacks striations; involuntary control; propels substances along internal passageways; mostly walls of hollow organs

Question 13

Integral Proteins

Answer 13

firmly imbedded in, or attached to lipid bilayer

Question 14

Peripheral proteins

Answer 14

attach to membrane surface

Question 15

Simple Diffusion

Answer 15

molecules move from a region where they are more concentrated to an area where they are less concentrated

Question 16

Osmosis

Answer 16

the simple diffusion of water across a membrane; water moves from a higher concentration to a lower concentration

Question 17

Endocytosis

Answer 17

• mechanism by which particles enter cells
• Two types: Phagocytosis & Pinocytosis

Question 18

Phagocytosis

Answer 18

• Type of endocytosis
• “cell eating” – primary nonspecific defense mechanism of the host; many white blood cells carry out this function
  -nonselective or nonspecific

Question 19

Pinocytosis

Answer 19

• Type of Endocytosis
• “cell drinking” – many cells of the digestive system will use this process to sample the nutrients of the tissue fluid
• nonselective or nonspecific

Question 20

Exocytosis

Answer 20

mechanism that moves substances out of the cell; secretory cells will use this process

Question 21

Cytoplasm

Answer 21

• lies internal to plasma membrane
• Consists of cytosol, organelles, and inclusions

Question 22

Cytosol (cytoplasmic matrix)

Answer 22

• Jelly-like fluid in which other cellular elements are suspended
• Consists of water, ions, and enzymes

Question 23

Ribosomes

Answer 23

constructed of proteins and ribosomal RNA (rRNA)

Question 24

ribosomal RNA (rRNA)

Answer 24

• Site of protein synthesis
• Assembly process is called translation and is dictated by the DNA
• Instructions are carried out by the messenger RNA (mRNA)

Question 25

Endoplasmic reticulum

Answer 25

"network within the cytoplasm” - two types: rough er, smooth er

Question 26

Rough ER

Answer 26

- type of Endoplasmic reticulum - ribosomes stud the external surfaces - Cell’s membrane factory; produces the proteins of the the cell’s membrane, secretory proteins, digestive enzymes - Stores ionic calcium which acts as a signal for the beginning of many cellular events

Question 27

Smooth ER

Answer 27

- type of Endoplasmic Reticulum - consists of tubules in a branching network - No ribosomes are attached; therefore no protein synthesis - Lipid metabolism - Stores ionic calcium which acts as a signal for the beginning of many cellular events

Question 28

Golgi Apparatus

Answer 28

- a stack of three to ten disk-shaped envelopes - Sorts products of rough ER and sends them to the proper destination - Often referred to as the “post office” of the cell

Question 29

Mitochondria

Answer 29

- generate most of the cell’s energy (ATP); most complex organelle - Often referred to as the “powerhouse” of the cell - Energy is stored in chemical bonds of nutrient molecules to produce ATP (energy for the cell) (ATP stands for adenosinetriphosphate)

Question 30

Lysosomes

Answer 30

- membrane-walled sacs containing digestive enzymes - Digest unwanted substances

Answer 31

- membrane-walled sacs of oxidase and catalase enzymes - Enzymes neutralize free radicals and break down poisons - two types: Oxidase & Catalase - Break down long chains of fatty acids - Are numerous in the liver and kidneys

Question 32

Oxidase

Answer 32

an enzyme that breaks down free radicals and forms hydrogen peroxide

Question 33

Catalase

Answer 33

an enzyme that further breaks down the hydrogen peroxide into H2O and O2 Break down long chains of fatty acids

Question 34

Cytoskeleton

Answer 34

- “cell skeleton” – an elaborate network of rods - Serves as the cell’s bones, muscles, and ligaments

Question 35

Cytoplasmic Inclusions

Answer 35

- Temporary structures - not present in all cell types - May consist of pigments, crystals of protein, and food stores

Question 36

Nucleus

Answer 36

- control center of cell - DNA directs the cell’s activities - Nucleus is approximate 5µm in diameter - Genetic information of the cell - Nucleus is surrounded by a nuclear membrane also called a nuclear envelope

Question 37

Nucleolus

Answer 37

– “little nucleus” – in the center of the nucleus - Contains parts of several chromosomes - Site of ribosome subunit manufacture

Question 38

Cellular Diversity

Answer 38

Specialized functions of cells relates to: Shape of cell Types of organelles present

Question 39

Tissue

Answer 39

a group of closely associated cells that perform related functions and are similar in structure

Question 40

Organ

Answer 40

a discrete structure made up of more than one tissue

Question 41

Four Basic Tissue Types and Basic Functions

Answer 41

Epithelial tissue – covering and lining Connective tissue – support Muscle tissue – movement Nervous tissue – control / communication

Question 42

Epithelial Tissue

Answer 42

- Covers a body surface or lines a body cavity - Forms most glands - Functions of epithelium:Protection Absorption, secretion, ion transport, Filtration - Forms slippery surfaces

Question 43

Special Characteristics of Epithelia

Answer 43

Cellularity, support by connective tissue, avascular, innervated, regeneration