Chapter 3

Question 1

What are the smallest unit of life?

Answer 1

Cells

Question 2

4 parts of a cell:

Answer 2

Plasma membrane
Cytoplasm
Nucleus
Cytosol

Question 3

-Double layer of phospholipids with embedded proteins
-Separates outside of cell from inside of cell
-Controls what is passed through cell
-Active barrier separating intracellular fluid from extracellular material

Answer 3

Plasma membrane

Question 4

Substance that acts as glue to hold cells together

Answer 4

Extracellular matrix

Question 5

Cellular secretions

Answer 5

Extracellular fluids

Question 6

What are plasma membrane functions?

Answer 6

-Mechanical barrier
-Selective permeability
-Electrochemical gradient
-Communication/Cell recognition
-Cell signaling

Question 7

What are the components of the plasma membrane?

Answer 7

Phospholipid bilayer
Integral membrane proteins
Peripheral membrane proteins
Glycocalyx

Question 8

Lipid Bilayer

Answer 8

75% phospholipids
5% glycolipids
20% cholesterol

Question 9

-Firmly inserted into membrane
-Hydrophobic and hydrophilic regions
-Functions: transport proteins, receptors, enzymes

Answer 9

Integral membrane proteins

Question 10

-Loosely attached to integral proteins
-Include filaments on intracellular surface used for plasma membrane support

Answer 10

Peripheral membrane proteins

Question 11

Glycocalyx

Answer 11

-Consist of carbohydrates sticking out of cell surface
-Glycolipids and glycoproteins

Question 12

What are three ways that cells are bound together?

Answer 12

Tight junctions
Desmosomes
Gap junctions

Question 13

Tight junctions

Answer 13

Impermeable junctions that form continuous seals around the cells and prevent molecules from passing through intercellular space

Question 14

Desmosomes

Answer 14

Anchoring junctions that bind adjacent cells together and act like molecular “velcro”

Question 15

Gap junctions

Answer 15

Communicating junctions that allow ions and small molecules to pass
Particularily important for communication in heart cells and embryonic cells

Question 16

Cytoplasm

Answer 16

-All cellular material is located between plasma membrane and nucleus
-Cytosol, Inclusions, Organelles

Question 17

Cytosol

Answer 17

Gel-like solution made of water and soluble molecules such as proteins, salts, sugars, etc.

Question 18

Mitochondria

Answer 18

Site of ATP synthesis, powerhouse of cell

Question 19

Sites of protein synthesis

Answer 19

Ribosomes

Question 20

Sugar groups are attached to proteins within the cistems
Proteins are bound in vesicles for transport to Golgi apparatus and other sites
External face synthesizes phospholipids

Answer 20

Rough endoplasmic reticulum

Question 21

Membranous system of sacs and tubules; free of ribosomes
Site of lipid and steroid (cholesterol) synthesis, lipid metabolism, drug detoxification, calcium storage

Answer 21

Smooth ER

Question 22

A stack of flattened membranes and is associated with vesicles close to the nucleus
Packages, modifies, and segregates proteins for secretion from cell

Answer 22

Golgi apparatus

Question 23

Membranous sacs containing catalase and oxidase enzymes
Detoxify substances

Answer 23

Peroxisomes

Question 24

Breaks down hydrogen peroxide

Answer 24

Catalase

Question 25

Membranous sacs containing acid hydrolases Sites of intracellular digestion and recycling

Answer 25

Lysosomes

Question 26

Cylindrical structures made of tubulin proteins Support the cell and give it shape; involved in intracellular and cellular movements Form centrioles, cilia, flagella, if present

Answer 26

Microtubules

Question 27

Protein fibers; composition varies Stable cytoskeletal elements; resist mechanical forces acting on the cell

Answer 27

Intermediate filaments

Question 28

Fine filaments composed of protein actin Involved in muscle contraction and other types of intracellular movement Helps form the cell's cytoskelton

Answer 28

Microfilaments

Question 29

Varied; includes stored nutrients such as lipid droplets and glycogen granules, protein crystals, pigment granules Storage for nutrients, wastes, and cell products

Answer 29

Inclusions

Question 30

What are three cellular extensions?

Answer 30

Cilia Microvilli Flagellum

Question 31

Short cell surface projections, each cilium contains of nine pairs of microtubules surrounding a central pair Coordinated movement creates a unidirectional current that propels substances

Answer 31

Cilia

Question 32

Like cilium, but longer; only example in humans is sperm tail Propels the cell

Answer 32

Flagellum

Question 33

Tubular extensions of the plasma membrane; contain a bundle of actin filaments Increase surface area of absorption

Answer 33

Microvilli

Question 34

Nuclear envelope Nucleolus Chromatin

Answer 34

Parts of the nucleus are...

Question 35

Houses DNA Contains the genetic library of blueprints for synthesis of nearly all cellular proteins

Answer 35

Nucleus

Question 36

Folds inside of of mitochondria

Answer 36

Cristae

Question 37

Double membrane barrier, outer layer is continuous with rough ER, inner layer is a network mesh of proteins that maintains nuclear shape

Answer 37

Nuclear envelope

Question 38

Allow substances to pass into and out of nucleus

Answer 38

Nuclear pores

Question 39

Site of ribosomal subunit manufacture

Answer 39

Nucleolus

Question 40

Consists of histone proteins, DNA, and RNA Arranged in fundamental units called nucleosomes

Answer 40

Chromatin

Question 41

Consist of DNA wrapped around a histone

Answer 41

Nucleosomes

Question 42

Paired cylindrical bodies, each composed of nine triplets of microtubules Organize microtubule network Form spindle and asters Form bases of cilia and flagellum

Answer 42

Centrioles

Question 43

Contain genes, condensed chromatin

Answer 43

Chromosomes

Question 44

Series of changes a cell undergoes from the time it is formed until it reproduces Major periods - interphase, mitotic phase

Answer 44

Cell Cycle

Question 45

Cell carries out its routine activities and prepares for cell division Nuclear material is in uncondensed chromatin state

Answer 45

Interphase

Question 46

G1- vigorous growth S - DNA replication G2 - division preparation

Answer 46

What are the three phases of interphase?

Question 47

Division of the cell occurs, consists of two distinct events 1) Mitosis 2) Cytokinesis

Answer 47

M (Mitotic) phase

Question 48

Division of the nucleus, in which duplicated DNA is distributed to new daughter cells

Answer 48

Mitosis

Question 49

Begins in late anaphase and continues through and beyond telophase Ring of actin microfilaments contracts to form a cleavage furrow Two daughter cells are pinche apart

Answer 49

Cytokinesis