Ch 3 - outline

Question 1

overview of cells

Answer 1

• size and shape
• composition: cytoplasm, organelles, cell interior surrounded by plasma membrane

Question 2

what are the 3 main parts of a cell?

Answer 2

1. plasma membrane
2. cytoplasm
3. nucleus

Question 3

Plasma membrane

Answer 3

structure: forms outer layer is a thin 2 layer “wall”
- wall of phospholipids studded with proteins
functions: cholesterol - between the layers to prevent breakage
4. carbohydrate chains on surface = ID of cell type

Question 4

Cytoplasm

Answer 4

1. the fluid between the cell wall and the nucleus
2. cytoskeleton: made up of microfilaments (thread) and microtubules
3. organelles

Question 5

what are the organelles found in cytoplasm of a human?

Answer 5

1. ribosomes
2. endoplasmic reticulum
3. golgi apparatus
   4.mitochondria
4. lysosomes
5. centrosome

Question 6

Ribosomes

Answer 6

• made up of 2 tiny subunits of rRNA
• makes enzymes and protein
  “ protein factory”
• free : makes protein to be used by the cell
• attached to rough ER: protein is secreted out

Question 7

Endoplasmic Reticulum

Answer 7

a system of membranes forming a network of connecting sacs and canals that wind back and forth through cytoplasm carrying substances.
Rough ER collects, folds, and transports new proteins. (attached ribosomes makes it rough)
Smooth ER synthesizes chemicals; makes new membrane. manufactures lipids, carbs, proteins for membrane .

Question 8

Golgi Apparatus

Answer 8

“chemical processing and packaging center”
Tiny flattened sacs stacked on one another near the nucleus.
bubbles/sacs(vesicles) break off smooth ER carrying new proteins to golgi apparatus.

Question 9

Mitochondria

Answer 9

• 1 inner and 1 outer membrane layers containing sacs
• inner layer forms folds.
• “power plant”
• enzymes involved with energy releasing chemical reactions to “recharge” (cellular respiration)
• each contains 1 DNA molecule

Question 10

Lysosomes

Answer 10

“digestive bags”
- membrane enclosed packets(sacs) containing digestive enzymes.
- eats microbes

Question 11

Centrosome

Answer 11

• microtubule organizing region of the cytoskeleton near the nucleus
• Centrioles: paired organelles found within the centrosome at right angles during cell reproduction

Question 12

Nucleus

Answer 12

• controls cell because it contains most of the genetic code (genome), instructions for making proteins, which determines cell structure and function.
• contains nuclear envelope (2 membranes), & nucleoplasm (nucleolus & chromatin granules)
• 46 chromosomes

Question 13

Nucleolus

Answer 13

a dense region of the nuclear material that is critical in protein information

Question 14

Apoptosis

Answer 14

cell suicide to make space for newer cells

Question 15

what are the 3 major types of cell extensions?

Answer 15

1. microvilli
2. cilia
3. flagella

Question 16

Microvilli

Answer 16

small, fingerlike projections of the plasma membrane that increases surface area and produce slight movements that enhance absorption by the cellc

Question 17

Cilia

Answer 17

hair like extensions with inner microtubules found on free or exposed surfaces of cells.
- sensory functions
can move in wave like motion to move mucus

Question 18

Flagella

Answer 18

single projection extending from cell surface.
“tails” of sperm cells

Question 19

the plasma membrane allows what are the two types of transport processes that allows substances to enter the cell?

Answer 19

1. passive transport (no energy)
2. active transport (energy)

Question 20

what are some important Passive Transport Processes that move substances through membranes?

Answer 20

1. diffusion
2. dialysis
3. osmosis
4. filtration

Question 21

Diffusion

Answer 21

movement of particles through membrane from an area of high concentration to an area of low concentration.
* scatter evenly
(think: sugar in coffee)
ex: movement of CO2 out of cells; movement of sodium ions into nerve cells as they conduct an impulse

Question 22

Osmosis

Answer 22

passive movement of water through a selectively permeable membrane in the presence of at least one impermeant solute.

• think: youre making the surface area (water) smaller on the left so that the percentage of the albumin in left water is equal to the right since now the right side has more water (surface area) to accommodate that it has more albumin on that side creating an equilibrium between the two.

Question 23

Filtration

Answer 23

movement of water and small solute particles, but not larger particles, through a filtration membrane; movement occurs from an area of high pressure to an area of low pressure.
ex: in the kidney, movement of water and small solutes from blood vessels but lack of movement by blood proteins and blood cells; begins formation of urine.

Question 24

semipermeable

Answer 24

substances small enough to pass can pass through but larger particles cannot

Question 25

permeabillity

Answer 25

the ability of a membrane to allow substances to pass through it

Question 26

Solutes

Answer 26

substances dissolved in the water

Question 27

Dialysis

Answer 27

Some solutes move across a semipermeable membrane by diffusion and others do not. (think like a tea bag)

Question 28

Active transport process

Answer 28

involves the "uphill" movement of a substance through a living cell membrane "uphill" = from a lower to higher concentration * think: against the current

Question 29

what are 3 active transport processes?

Answer 29

1. Ion Pump 2. Phagocytosis 3. Pinocytosis

Question 30

Ion Pump

Answer 30

- complex membrane ex: potassium-sodium coupled pumps to allow both in and out at the same time.

Question 31

Phagocytosis

Answer 31

"cell eating" - engulf large particles in a vesicle as a protective mechanism used to destroy bacteria

Question 32

Pinocytosis

Answer 32

"cell drinking" - engulfs fluids or dissolved substances into cells

Question 33

who directs protein synthesis?

Answer 33

DNA and RNA

Question 34

what are DNAs base pairs?

Answer 34

adenine- thymine guanine-cytosine

Question 35

what dictates formation of enzymes and other proteins by ribosomes, thereby indirectly determining a cell's structure and function?

Answer 35

Genes

Question 36

RNA

Answer 36

- consist of molecules made from genes that do not code directly for proteins - regulates cell processes (protein synthesis) - subunits are made from nucleotides, ribose (sugar) and uracil instead of thymine

Question 37

Protein Synthesis

Answer 37

is the process of transferring genetic information from the nucleus into the cytoplasm where proteins are produced. requires: transcription and translation

Question 37

transcription

Answer 37

DNA separates to form messenger RNA (mRNA). mRNA then leaves nucleus to the cytoplasm to direct protein synthesis in the ribosomes and ER

Question 38

Translation

Answer 38

- translation of code in mRNA to synthesis proteins in cytoplasm in ribosomes. - Transfer RNA (tRNA) carries a specific amino acid and has an anticodon

Question 39

anticodon

Answer 39

a three base sequence that compliments the mRNA codon that signifies that amino acid during translation in protein synthesis. * think* codon = original pattern in DNA, anticodon is the opposite or the "significant other" of the codon sequence since they will always couple with the same "color" (fig 3-13 good example/explanation)

Question 40

what are the 5 phases of the cell life cycle?

Answer 40

1. Interphase 2. Prophase 3. Metaphase 4. Anaphase 5. Telophase *IP. MAT*

Question 41

Prophase

Answer 41

first stage of mitosis. - Chromatin granules organize into visible chromosomes and attach at the centromere. - nuclear envelopes disappear, spindle fibers appear

Question 42

Metaphase

Answer 42

second stage - Chromosomes align across center of cell - spindle fibers attach to each chromatid

Question 43

Anaphase

Answer 43

third stage - centromeres break apart & move away from the center "cleavage furrow" = cell is starting to divide into 2

Question 44

Telophase

Answer 44

fourth stage - cell division is complete - nuclear envelope and nuclei reappear - cytoplasm & organelles divide equally

Question 45

Interphase

Answer 45

cell not actively dividing