Ch. 4

Question 1

Plasma Membrane: Function

Answer 1

1) to regulate the concentration of substances inside the cell
2) helps contain the cytoplasm

Question 2

Plasma Membrane: Components

Answer 2

components: two adjacent sheets of phospholipids; 2 kinds of proteins: peripheral membrane protein (surface protein) serves as a marker, integral membrane protein (transmembrane proteins) serves as channels

Question 3

prokaryotic cells: components and function of every component

Answer 3

flagella/um: helps with mobility; helps with phototaxis, chemotaxis; Helps with a survival
Pili: exchanges genetic material during conjugation; makes bacteria antibiotic resistant
chromosomal DNA: localized in our region called the nucleoid
cell membrane/plasma membrane
ribosomes: protein synthesis
Peptidoglydan cell wall:made from proteins and carbohydrates and it’s used for protection
Capsule: polysaccharide; only found in some bacteria not in Archaea; Makes bacteria dormant; makes bacteria resistant to disinfectant but not to concentrated bleach

Question 4

differences between plant and animal cells

Answer 4

1) animal cells have no distinct shape. Plants have a rigid shape.
2) plants have a central vacuole, Which regulates water concentration. it also starts nutrients, and maintains pressure against cell walls.
3) centrosomes are always present and animal cells, but are only present in plant cells when they are ready to divide.
4) plants have a specialized organelle called chloroplasts which carry out photosynthesis.

Question 5

nucleus

Answer 5

structure: spherical or oval shaped structure; nuclear envelope(double membrane that separates necklace from cytoplasm), Nuclear pore (numerous openings in nuclear envelope, controls movement of substances between nucleus and cytoplasm)
function: contains DNA and molecules called chromosomes; each chromosome consists of a single molecule of DNA and associated packaging proteins; a chromosome contains thousands of hereditary units called genes

Question 6

Nucleolus

Answer 6

produces ribosomes

Question 7

rough endoplasmic reticulum

Answer 7

structure: network of membranes in the shape of flattened tubules or sacs; connected to nuclear envelope; surface studded with the ribosomes
function: produces various proteins

Question 8

smooth endoplasmic reticulum

Answer 8

structure: network of membranes in the shape of flattened tubules or sacs; does not have ribosomes
function: synthesize fatty acids and steroids and it detoxifies the drugs

Question 9

Golgi apparatus/complex

Answer 9

structure: System of flattened sacs (cisternae)
function: synthesizes carbohydrates; modify, sword, and package proteins for transport to different destinations; proteins are transported by various vesicles (lysosomes, secretory vesicles)

Question 10

lysosome

Answer 10

structure: Membrane bound vesicles that contain hydrolytic enzymes. The lysosomes arise from the Goldie apparatus.
function: when that particles such as virusesor bacteria are ingested by phagocytosis, the lysosome fuse with the particle containing vesicle, called the phagosome and delivers the hydrolytic enzymes. Lysozymes also fuses with organelle such as old mitochondria. This results in the distraction and recycling of the structures.

Question 11

Peroxizomes

Answer 11

structure: membrane-bound cellular organelle that contains mostly enzymes. Found in the liver. Converts ethanol to glucose.
function: lipid metabolism, chemical detoxification and carry out oxidation reactions that break down fatty acids and amino acids.

Question 12

mitochondria

“The powerhouses of the cell”

Answer 12

structure: have in there and outer mitochondrial membrane similar to plasma membrane; cristae– The series of folds of the inner membrane, matrix – the large central fluid filled cavity
function: generate ATP(more prevalent in physiologically active cells: muscles, liver and kidneys); Self replicate during times of increased demand or before cell division; contain own DNA(inherited from mother only), Evolved from symbiotic relationship

Question 13

chloroplasts

Answer 13

found only in plant cells, contains the pigment chlorophyll, organelle where photosynthesis takes place

Question 14

cytoskeleton

Answer 14

structure: collection of protein filaments and tubules
function: provide support, organization and movement to cell

Question 15

centriole/centrosome

Answer 15

structure: located near the nucleus, consists of two centrioles and pericentriolar material
function: build cytoskeleton and mitotic spindle during cell division; Build cytoskeleton found in cilia and flagella

Question 16

proteasome

Answer 16

continuously destroy unneeded, damaged, or faulty proteins; found in the cytosol and the nucleus

Question 17

three types of cytoskeleton filaments

Answer 17

1) microfilaments: composed of Actin protein, six nanometers thick
2) intermediate filaments: helps hold epithelial cells together; Resist stresses on cells; Line nuclear envelope; toughens hair and nails
3) microtubules: Hold organelles in place, serve as tracts for intracellular transport proteins, give the cilia and flagella motility

Question 18

Endosymbiosis

Answer 18

mitochondria used to be a prokaryotic cell, but formed a relationship with a eukaryotic cell. The prokaryotic cell benefited by getting the protection, and the eukaryotic cell benefited by getting energy.

Question 19

osmosis and diffusion

Answer 19

osmosis: movement from low concentration of nutrients to high concentration of nutrients
diffusion: movement from high concentration of nutrients to low concentration of nutrients
osmosis: outside to inside
diffusion: inside to outside

Question 20

what is passive transport?

Answer 20

passive transport: the movement of substances across the plasma membrane without the expenditure of cellular energy. During passive transport, materials move by simple diffusion or by facilitated diffusion through the membrane, down their concentration gradient.

Question 21

what is active transport?

Answer 21

Active transport: uses energy from ATP to move material across the plasma membrane in a direction against a concentration gradient. Active transport me take place with the help of proton pump or through the use of vesicles.

Question 22

hypertonic

Answer 22

anything above .9%

shrivels and dies

Question 23

hypotonic

Answer 23

below .9%

swells up

Question 24

isotonic

Answer 24

equal to .9%

stays the same

Question 25

phagocytosis

Answer 25

uptake of solids (bacteria cells or an organic fragment)

Question 26

pinocytosis

Answer 26

uptake of liquids

Question 27

receptor mediated cytosis

Answer 27

uptake of macromolecules

Question 28

Types of Microscopes

Answer 28

1) Compound Light Microscope
2) Dissecting Microscope
3) Scanning Electron Microscope