Exam 1

Microtubule Function

(1) internal i. cellular trafficking ii. movement of chromosomes during cell division (mitotic spindle) (2) external i. movement of extracellular materials (cilia) ii. propulsion of sperm (flagella)

Nucleolus organization

(1)nucleolar organizer DNA (NO) à encodes rRNA (2) pars fibrosa (PF) --> rRNA (3) pars granulosa (PG) --> maturing ribosomes = (rRNA + proteins)

Hierarchy of cellular components levels

(from top to bottom) L1 = small organic molecules L2 = macromolecules L3 = supramolecular structures L4 = organelles and other structures L5 = the cell

DNA synthesis (S Phase)

(semi-conservative replication) One strand of the parent double helix is conserved in each new DNA molecule

Surface Specialization Cilia

(~5-10µm long) and flagella (much longer) 1. motile 2. also known as axoneme 3. 9 doublets of microtubules surrounding 2 single microtubules (9+2) 4. motor protein is axonemal dynein 5. requires ATP as energy source 6. supporting proteins maintain microtubular arrangement 7.basal body a. cytoplasmic base of axoneme b. composed of 9 triplets of microtubules with no central microtubules (9+0)

collagen types

*table 17.2* slide 17 ECM ppt

Lysosomes

-- Contain many hydrolytic enzymes (acid hydrolases) -- H+ pumps maintain acidic internal environment -- Contains over 40 hydrolytic enzymes-lipases, proteases, nucleases and carbohydrases

Lysosomes

-- Small organelles, but readily visualized by EM or light microscopy -- Form by budding off of Golgi complex -- Enzymes are active in acidic environment Functions: --immunological defense --cellular recycling --apoptosis (via autolysis)

Smooth Endoplasmic reticulum

-- no ribosomes - no protein synthesis -- synthesis of lipids and steroids -- glycogen metabolism -- detoxification of some drugs, --- xenobiotics --- sequesters and releases Ca2+ ions in muscle cells

Preparation from Mitosis occurs in what phase of the cell cycle? A. G1 B. G2 C. GO D. G3

B. G2

rough endoplasmic reticulum (RER)

--- surface is associated with many ribosomes --- growing polypeptide chain glycosylated and released in lumen --- proteins packaged into vesicle and released

plasma membrane function

--Acts as dynamic barrier between internal and external environment --Maintains chemical and electrical gradient --Basic structural unit-phospholipid bilayer- fluid mosaic membrane

amino acid affect on protein

--Amino acid sequence determines the three-dimensional structure, thus the function, of a protein --With 20 different amino acids, a nearly infinite variety of protein sequences is possible

Intermediate filaments

--Fibrous, not globular protein --More stable --Made up of different protein subunits in different cells --Provide structural strength more diverse in composition than other cytoskeletal elements

Example of Medical application

--Inhibitory compounds used in cancer chemotherapy to block activity of mitotic spindle in rapidly growing tumor cells --Class V intermediate filaments defects are found in muscular dystrophy

Human cells have three basic parts

--Plasma membrane—flexible outer boundary --Cytoplasm—intracellular fluid containing organelles --Nucleus—control center

Macromolecules/Polymers

--Proteins (Polymers of amino acids) --Polysaccharides (Polymers of sugars, carbohydrates) --Nucleic acids (polymers of nucleotides) --Lipids (made of variety of different molecules) Note: Except for lipids, these macromolecules are also called polymers

Examples of Medical Application

--Proteins of Zonula Occludens provide targets for by some bacteria which causes food poisoning --Blistering diseases involving the epidermis are due to abnormal desmosome function

Monomeric nucleotides

--Sources of chemical energy in cell (usually ATP) --Cell signaling (various nucleotides

Nucleic acids are

--are the largest molecules in the body. --Nucleic acid monomers called nucleotides Composed of nitrogen base, a pentose sugar, and a phosphate group

Domains

--compact units connected by the short peptide chains --relatively independent on other domains --may exhibit different biological activities Note: Proteins with multiple functions usually have a separate domain for each function. --eg. for proteins that are enzymes, one domain carries out catalytic activity another regulates enzymatic activity.

Peroxisomes (Microbodies) function

--contain enzymes used for detox of harmful substances --oxidases à neutralize free radicals and other toxins, generating H2O2 --catalases --> H2O2 --> H2O + O2 --also oxidize long-chain fatty acids (up to 22 carbon atoms)

Glycoproteins

--covalently linked sugar residues on outside of cell A. sugar act as recognition sites B. important as self determinant for immune system

Nuclear envelope

--double membrane: outer layer continuous with endoplasmic reticulum --nuclear pores: regulate passage of material between nucleus and cytoplasm

Golgi apparatus function

--further post-translational modifications --protein sorting, packaging, trafficking --processing and packaging of proteins secreted from RER

Quaternary structure

--level of organization concerned with subunit interactions and assembly --specifically to multimeric proteins --Some proteins consist of multiple identical subunits; others, like hemoglobin, contain two or more types of polypeptides

Integrins are:

--plasma proteins --Binding sites for extracellular matrix components: -Collagen -Fibronectin -laminin

Tertiary structure

--reflects the unique aspect of the amino acid sequence because it depends on interactions of the R groups --neither repetitive nor easy to predict --results from the sum of hydrophobic residues avoiding water, hydrophilic residues interacting with water, the repulsion of similarly charged residues, and attraction between oppositely charged residues eg. Ribonuclease

Peroxisomes structure

--resemble lysosomes --may contain dark staining crystalline core composed of enzymes

Golgi complex (apparatus)

--stacks of flattened sacs --completes glycosylation of glycoproteins Polarity: a)cis face = "receiving side" --> fuses with vesicles released from RER containing proteins b)trans face = "shipping side" --> processed proteins secreted in vesicles bound for cell membrane

nucleic acids uses

--storage of genetic information-DNA --transient expression of genetic information-RNA --protein synthesis-RNA

Carrier molecules

-For protein synthesis, amino acids are linked to carriers called transfer RNA (tRNA) -Sugars (often glucose) that form polysaccharides are activated by linking them to ADP (adenosine diphosphate), or UDP (uridine diphosphate) -For nucleic acids the nucleotides themselves are high-energy molecules (ATP, GTP)

Hemidesmosomes

-instead of cadherins attaching adjacent cells, integrins attach cell to components of the extracellular matrix. It anchors cytoskeleton to the basal lamina.

Adherens junctions (zonula adherens)

-membrane proteins (Ca++ dependent cadherin) of adjacent cells bind to adhere cells to each other -actin microfilaments in cell cortex anchor cadherins transmembrane glycoproteins of each cell that interact in the presence of calcium. It strengthens the tissue.

Matching Macromolecule: 1. DNA 2. Cellulose 3. Hemoglobin 4. Glycogen 5. Triglyceride 6. Starch 7. Collagen Monomer: A. Glucose B. Nucleotide C. Amino Acid D. Fatty acids

1 = B 2 = A 3 = C 4 = A 5 = D 6 = A 7 = C

Microfilaments function

1) structural support (e.g. cell cortex) (2) cleavage furrow during cell division (dividing cells) (3) structural basis of microvilli (e.g. in gut epithelium) (4) muscle contraction (muscle cells) • (4) amoeboid movement (phagocytic cells) • (5) cytoplasmic streaming (some cells)

Proteoglycans

1. Core protein 2. Attached glycosaminoglycans a. dermatan sulfate b. chondroitin sulfate c. keratan sulfate d. heparan sulfate

Regulation of the Cycle (internal)

1. Cyclins: Proteins which bind to specific kinases (cyclin-dependent kinases - CDKs) to regulate events of interphase. All eukaryotes have multiple cyclins, each of which acts during a specific stage of the cell cycle. (In organisms with multiple CDKs, each CDK is paired with a specific cyclin.) For example: M- phase cyclins form M-CDK complexes and drive the cell's entry into mitosis.

S Phase

1. DNA synthesis 2. 6-8 hours 3. semiconservative replication maintains integrity of genetic information 4. centrioles required for mitotic spindle replicated

Cell cycle regulation

1. G2-M transition: influenced by cell size, DNA damage, DNA replication 2. Metaphase-Anaphase transition: influenced by chromosome attachments to spindle 3. Restriction Point (start): influenced by growth factors, nutrients, cell size, DNA damage

Hierarchy of cellular components

1. Small organic molecules are synthesized from simple inorganic substances and are polymerized to from macromolecules. 2. The macromolecules then assemble into supramolecular structures that make up organelles and other cellular structures and, ultimately, the cell itself.

Components of ECM

1. Structural proteins such as collagens and elastins, which provide strength and flexibility 2. Protein-polysaccharide complexes, proteoglycans, that provide the matrix 3. Adhesive glycoproteins, fibronectins laminins, and integrins that allow cells to attach to the matrix

Functions of membrane proteins

1. Transport 2. Receptors for signal transduction 3. Attachment to cytoskeleton and extracellular matrix 4. Enzymatic activity 5. Intercellular joining 6. Cell-cell recognition

mitochondrion structure

1. double-membrane -inner membrane folds called cristae -inner membrane contains carrier proteins of electron transport system and ATP synthase 2. matrix contains enzymes of TCA cycle and b-oxidation of fatty acids 3. contains circular DNA and ribosomes - similar to prokaryotic cells 4. semi-autonomous

G2 Phase

1. gap 2 or post synthetic 2. relatively uniform in length; 3-6 hours 3. preparation for mitosis 4. checkpoint for repair of DNA

GO Phase

1. in cells that can exit the cycle for varying lengths of time a. cardiac muscle and neurons permanently exit 2. Entered from G1

Glycosaminoglycans (GAGs) or mucopolysaccharides

1. linear polysaccharides formed of repeating disaccharides a. uronic acid (can be glucuronic or iduronic acid) b. hexosamine (can be glucosamine or galactosamine) 2. covalently linked to core protein to form proteoglycan 3. exception: hyaluronic acid not linked to protein 4. abundant sulfate and carboxyl groups make molecules hydrophilic and negatively charged

Apoptosis (Embryonic development)

1. normal reorganization of tissues 2. example: developing hand and foot

Karyokinesis steps

1. prophase 2. metaphase 3.anaphase 4. telophase

Macromolecules synthesis

1. stepwise polymerization of similar or identical monomers 2. Addition occurs with the removal of a water molecule ( condensation reaction ) 3. Monomeric units are joined together by activated monomers before condensation occurs 4. Activation involves coupling of monomer to a carrier molecules forming activated monomer 5. Energy needed is ATP 6. Because of the way they are synthesized, have an inherent directionality. Both ends are different

Collagen synthesis (ECM)

1. synthesis (RER) → preprocollagen, primarily glycine 2. hydroxylation (RER) of proline and lysine (vitC required) 3. glycosylation (RER) to form triple helix → procollagen 4. exocytosis into extracellular space 5. proteolytic processing → tropocollagen 6. cross-linking (covalent lysine-hydroxylysine cross-linkage, Cu required) → collagen fibrils

Endomembrane system function

1. synthesis of lysosomes, secreted, & membrane proteins -nucleus --> mRNA transcription -RER --> translation of mRNA; polypeptide modification -transport vesicles --> from RER to Golgi -Golgi --> further modification, packaging, and shipping a) lysosomes OR b) transport/secretory vesicles carry protein to plasma membrane -inner mitochondrial membrane - electron transport chain

Apoptosis (Adult tissue)

1. to balance cell divisions 2. removes cells that are damaged or ineffective 3. nucleus condenses and breaks up 4. cell surface blebs and becomes target for phagocytosis 5. does not initiate an inflammatory response

collagen organization

1. type I - ubiquitous; largest fibers 2. type II - hyaline and elastic cartilage: fibrils only 3. type III - reticular 4. type IV - no fibers; meshwork; in basal lamina

G1 Phase

1. variable in length 2. gap 1 or presynthetic phase 3. cell growth 4. protein synthesis 5. checkpoint prior to entry into S a. is environment favorable for division b. is DNA intact

Organelles of Eukaryotes

1.Nucleus 2.Endoplasmic reticulum 3.Golgi complex (apparatus) 4.Lysosomes 5.Mitochondrion 6.Peroxisomes 7.Ribosomes

Surface Specialization Sterocilia

1.long branched microvilli 2.increase surface area for transport across membrane 3.increase surface area for transport across membrane

Plasma membrane proteins are amphipathic

3 types: --Integral proteins --Extrinsic (peripheral) proteins --Glycoproteins

axoneme complex

9 doublets + 2 singlets (9 + 2 arrangement) forms body of cilia and flagella

Secondary Structure

Either an alpha helix or beta pleated sheet. Determined by hydrogen binding within the polypeptide

Glycogen is found in plant cells? A. True B. False

B. False

Hydrogen bonds are very strong and are very hard to break. A. True B. False

B. False

Internal regulation of cell cycle is dependent on different types of growth factors. A. True B. False

B. False

Transcription and translation both occur in the cytoplasm? A. True B. False

B. False

Base pairing and genetic codon

A + T/U = 2 hydrogen binds C + G = 3 hydrogen bonds

sister chromatid split and migrate toward the opposite pole A) Anaphase B) Telophase C) prophase D) Metaphase

A) Anaphase

What structural level is represented by the sequence of amino acids in a polypeptide chain? A) primary structure B) secondary structure C) tertiary structure D) quaternary structure

A) primary structure

Which of the following structures would aid a cell in allowing absorption? MACA A) stereocilia B) microvilli C) cilia D) flagella

A) stereocilia B) microvilli

Identify the intramolecular interaction or bonding found in tertiary structure of proteins? MACA A. Covalent B. Hydrophobic C. Hydrogen D. Ionic

A. Covalent B. Hydrophobic C. Hydrogen D. Ionic

Hemoglobin molecule is made of : A. Three polypeptide chain A. Four poly peptide chain B. Only one chain C. None of the above

A. Four poly peptide chain

Surface Specialization Microvilli, Sterocilia, Cilia

A. Function: 1.to increase surface area 2. to move substances across surface

Which of the following characteristics for mitochondria is correct? MACA A. Has Inner membrane named Cristae B. Has its own DNA C. Contains ribosomes D. Enzymes for TCA E. It is a storage of glycogen

A. Has Inner membrane named Cristae B. Has its own DNA C. Contains ribosomes D. Enzymes for TCA

Type II collagen fiber is found in: MACA A. Hyaline cartilage B. Basal lamina C. Elastic cartilage D. Basement membrane

A. Hyaline cartilage C. Elastic cartilage

What is the type of the bond between amino acids in a primary structure? MACA A. Peptide B. covalent bond C. Hydrophobic interaction D. Noncovalent bond

A. Peptide B. covalent bond

Extracellular Matrix function

A. Reservoir for water, ions, nutrients, hormones, cell signaling molecules, etc. B. Maintain strength and rigidity of tissue C. Maintain shape of tissue D. Medium through with nutrients and metabolic wastes exchanged

Protein structure represented by alpha-helices or beta-sheets. A. Secondary structure B. Primary structure C. Tertiary structure D. Quaternary structure

A. Secondary structure

Basal lamina

A. Specialized extracellular matrix attaching epithelia to connective tissue B. Type IV collagen fibers in matrix C. Laminin 1. adhesive molecule of matrix 2. attachment sites for epithelial integrins and type IV collagen

Apoptosis does not cause inflammation. A. True B. False

A. True

Cancerous cells can divide so rapidly that they will often produce a glycocalyx that is different than the other cells in the body. This may result in cells of the immune system recognizing the tumorous cells as foreign and destroying them A. True B. False

A. True

Cholesterol is the most important for control of fluidity of membrane? A. True B. False

A. True

Collagen is a fibrous protein while hormones are Globular proteins A. True B. False

A. True

Glycogen, the storage form of glucose, is primarily stored in skeletal muscle and liver cells. A. True B. False

A. True

Reticular fibers are type III collagen fibers are produced by fibroblasts. A. True B. False

A. True

Integral proteins

A. extend through entire membrane B. transmembrane proteins

Nitrogenous bases in DNA

Adenine (A) Thymine (T) Cytosine (C) Guanine (G) A & G = purines C & T = pyrimidines

nitrogenous bases IN RNA

Adenine (A), Uracil (U), Cytosine (C), Guanine (G) A & G = purines C & U = pyrimidines

Generalized (Typical) Cell

All cells have some common structures and functions

Which organelle is responsible for processing and packaging proteins destined for export from the cell? A) endoplasmic reticulum B) Golgi apparatus C) lysosomes D) peroxisomes

B) Golgi apparatus

Chromosomes uncoil to form chromatin. A) Anaphase B) Telophase C) prophase D) Metaphase

B) Telophase

The electron microscope has revealed that one of the components within the cell consists of pinwheel array of 9 triplets of microtubules arranged to form a hollow tube. This structure is a ________. A)Microvilli B)centriole C) chromosome D) ribosome

B)centriole

Which of the following cytoskeletal elements is necessary for cleavage formation? A. Microtubules B. Actin filaments C. Centrioles D. Tubulin molecules

B. Actin filaments

You expect to find many gap junctions in ........ Than in .......... A. Epithelium..............Cardiac muscle B. Cardiac muscle....... Epithelium

B. Cardiac muscle....... Epithelium

Collagen is only secreted by fibroblast cells. A. True B. False

B. False

Which of the following is correct about Proteoglycans: A. They are long chains of polysaccharides called GAGS B. Gags plus proteins makes proteoglycans C. Chondroitin sulfate is a proteoglycan C. Dermatan sulfate is a proteoglycans D. All of the above are correct

B. Gags plus proteins makes proteoglycans

Plasma membrane proteins with covalently bound carbohydrates are called: A. Cholesterol B. Glycoproteins C. Phosphoproteins D. Phospholipids

B. Glycoproteins

Desmosomes bound to ... A. Actin filament inside the cell B. Intermediate filaments C. Flagella

B. Intermediate filaments

Colchicine is a drug that can prevent the formation of microtubules. Which is the most likely effect colchicine would have on cell division? A. It will enhance mitosis by moving chromosome toward the spindle equator. B. It will arrest mitosis by preventing the formation of spindle microtubules. C. It would have little or no effect on mitosis. D. It would delay mitosis by preventing S phase.

B. It will arrest mitosis by preventing the formation of spindle microtubules.

In which stage of mitosis do the identical sets of chromosomes line up along the midline or equator of the cell? A. Prophase B. Metaphase C. Anaphase D. Telophase

B. Metaphase

Gags are made of: A. polypeptides B. Polysaccharides C. Polynucleotides D. None of the above

B. Polysaccharides

Two or more polypeptide chains, each with its own tertiary structure. A. Secondary structure B. Primary structure C. Tertiary structure D. Quaternary structure

B. Primary structure

Which one of the following is an example of a disaccharide? MACA A. Fructose B. Sucrose C. Lactose D. galactose

B. Sucrose C. Lactose

Which of the followings have high affinity for silver staining? MACA A. Type I Collagen fibers B. Type III collagen fibers C. Elastic fibers D. Reticular fibers

B. Type III collagen fibers D. Reticular fibers

The plasma membrane is composed of A. a bilayer of proteins. B. a bilayer of phospholipids. C. carbohydrate molecules. D. carbohydrates and proteins. E. carbohydrates and lipids

B. a bilayer of phospholipids.

Stereocilia: A. are short B. are made of microvilli C. are motile D. none of the above

B. are made of microvilli

The genetic information is coded in DNA by the ________. A. regular alteration of sugar and phosphate molecules B. sequence of the nucleotides C. three-dimensional structure of the double helix D. arrangement of the histones

B. sequence of the nucleotides

What is the ratio of fatty acids to glycerol in triglycerides? A) 1:1 B) 2:1 C) 3:1 D) 4:1

C) 3:1

Starch is a ________. A) monosaccharide B) disaccharide C) polysaccharide D) triglyceride

C) polysaccharide

Centrioles move to opposite ends of the cell A) Anaphase B) Telophase C) prophase D) Metaphase

C) prophase

Nuclear envelope and nucleolus disintegrate A) Anaphase B) Telophase C) prophase D) Metaphase

C) prophase

Phospholipids make up most of the lipid part of the cell membrane. Since water exists on both the outside and inside of a cell, which of the following phospholipid arrangements makes the most sense? A) two back-to-back phospholipid layers with the non-polar tails facing out on both sides B) a single layer of phospholipids with the polar heads facing outside the cell C) two back-to-back phospholipid layers with the polar heads facing out on both sides D) a single layer of phospholipids with the polar heads facing inside the cell

C) two back-to-back phospholipid layers with the polar heads facing out on both sides

Mitosis includes: A. Cytokinesis B. Karyokinesis C. Both above

C. Both above

The most abundant protein in the body is? A. Elastin B. Laminin C. Collagen D. Integrin E. fibronectin

C. Collagen

Mitochondria ________. A. Contain digestive enzymes called acid hydrolyses B. Are single-membrane structures involved in the breakdown of ATP C. Contain some of the DNA and RNA code necessary for their own function D. synthesize proteins for use outside the cell

C. Contain some of the DNA and RNA code necessary for their own function

Cardiac muscle tissue undergoes a significant amount of physical stress due to its contractions. You would expect to see relatively large numbers of which of the following embedded within their plasma membrane? A. Transport proteins B. Tight junctions C. Desmosomes D. Glycolipids

C. Desmosomes

Which of the following glycoproteins is involved with cell movement? A. Integrins B. Laminin C. Fibronectin D. Chondroitin sulfate E. Hyaluronate

C. Fibronectin

Which of the following organizations of protein structure is the most important for determining the folding of polypeptide chain? A. Secondary B. Tertiary C. Primary D. Quaternary

C. Primary

Protein structure achieved among the side chains A. Secondary structure B. Primary structure C. Tertiary structure D. Quaternary structure

C. Tertiary structure

Basal lamina contains: A. Type IV collagen B. Laminin C. both of the above D. Neither of the above

C. both of the above

Which components of extracellular matrix is considered as water loving? MACA A. Fibroblasts B. Type I collagen fibers C. proteoglycans D. Gags E. Integrins

C. proteoglycans D. Gags

Globular (functional) proteins

Compact, spherical, water-soluble, and sensitive to environmental changes Tertiary or quaternary structure (3-D) Specific functional regions (active sites) Examples: antibodies, hormones, molecular chaperones, and enzymes

Chromosomes align on the spindle equator A) Anaphase B) Telophase C) prophase D) Metaphase

D) Metaphase

Which of the following Gags are not attached to proteins. A.Chondroitin sulfate B.Keratin sulfate C.Heparan sulfate D.Hyaluronate E.All could be attached to proteins

D. Hyaluronate

Which of the following organs contains many reticular fibers? MACA A. Bone B. Cartilage C. Tendon D. Spleen E. Lymph node

D. Spleen E. Lymph node

The apical most junctions which restrict membrane protein distribution in epithelial cells are called: A. Adhesive junctions B. Desmosomes C. Gap junctions D. Tight junctions

D. Tight junctions

What is the most dominant fat in the body? A. Cholesterol B. Phospholipid C. Terpene D. Triglyceride E. Cholesterol

D. Triglyceride

Which of the following is NOT a function of the smooth endoplasmic reticulum? A. lipid metabolism and cholesterol synthesis B. steroid-based hormone synthesis C. breakdown of stored glycogen to form free glucose D. protein synthesis in conjunction with ribosomes

D. protein synthesis in conjunction with ribosomes

Nucleosome structure

DNA and histones which has a core of 8 histones

Nucleic Acids classes/types

Deoxyribonucleic acid (DNA) Ribonucleic acid (RNA)

Bonds and Interactions Are Important in Protein Folding and Stability

Disulfide bonds Hydrogen bonds

Which of the following cellular organelles contain catalases? A. Golgi complex B. lysosomes C. Smooth Endoplasmic Reticulum D. Rough endoplasmic reticulum E. Peroxisomes

E. Peroxisomes

Which of the following is a GAG? A. dermatan sulfate B. chondroitin sulfate C. keratan sulfate D. heparan sulfate E. all of the above

E. all of the above

Which of the following is a general function for a fibrous protein? A. transport B. hormones C. body defense D. catalysis E. structural framework

E. structural framework

Classes of proteins

Enzymes: function as catalysts, increasing the rates of chemical reactions Structural proteins: physical support and shape Motility proteins: contraction and movement Regulatory proteins: control and coordinate cell function Transport proteins: move substances in and out of cells

Elastic fibers

Flexible and "stretchy" fibers that add elasticity to tissue

Sarcoplasmic reticulum

Functions: --Ca2+ storage and release

Regulation of the Cycle (external)

Growth factors: 1. bind to specific receptors on cell surface 2. send cytoplasmic signals to cellular components: Examples are epidermal growth factor in skin cells, Nerve growth factor in nerve cells

Classes of proteins (continued)

Hormonal proteins - communication between cells Receptor proteins - enable cells to respond to chemical stimuli from the environment Defensive proteins - protect against disease Storage proteins - reservoirs of amino acids

Mitochondria (cellular respiration)

Inner membrane --electron transport proteins --ATP synthase enzymes Matrix --enzymes for TCA cycle and fatty acid metabolism

Axoneme

Microtubules are also organized into larger, more stable arrays

Van der Waals interaction

Molecules with nonpolar covalent bonds may have transient positively and negatively charged region (weak interaction)

Mitochondria (def)

Powerhouse of the cell, organelle that is the site of ATP (energy) production

Nucleus (Production)

Produces ribosomal subunits in nucleolus and export them into cytoplasm for assembly into ribosomes

Collagens are

Responsible for the Strength of the Extracellular Matrix most abundant ECM component in animals is a family of closely related collagens, which form fibers with high tensile strength secreted by several types of cells in connective tissues including fibroblasts

Fibrous (structural) proteins

Strandlike, water-insoluble, and stable Most have tertiary or quaternary structure (3-D) Provide mechanical support and tensile strength Examples: keratin, elastin, collagen (single most abundant protein in body), and certain contractile fibers

Rough ER

Synthesis of: --secreted proteins --membrane proteins --lysosomal proteins

Cleavage furrow

The area of the cell membrane that pinches in and eventually separates the dividing cell

what type of barrier is the basal lamina?

The basal lamina is a structural support and a permeability barrier

Primary Structure

The first level of protein structure; the specific sequence of amino acids making up a polypeptide chain.

isoprene

The five carbon units that are joined together to form Vitamin A1 and carotenoid pigments

Quaternary Structure

The fourth level of protein structure; the shape resulting from the association of two or more polypeptide subunits.

Describe the glycocalyx and its functions.

The glycocalyx is the sticky, carbohydrate-rich area on the cell surface. It helps bind cells together and provides a highly specific biological marker by which cells can recognize each other.

Terminal Bar microscopy

Using light microscopy, it appears as a bar at the apical surface of the cell, wherein the structures listed cannot be resolved. With electron microscopy, the terminal bar can be visually disseminated into these structures.

Terminal Bar

a group of junctional complexes that attach adjacent epithelial cells on their lateral surfaces: The Tight Junctions (Zonula Occludens), zonula adherens and desmosomes (macula Occludens).

Ground substance

a highly hydrated (with much bound water), transparent, complex mixture of macromolecules, principally of three classes: glycosaminoglycans (GAGs), proteoglycans, and multiadhesisive glycoproteins

Phospholipids

a lipid consisting of a glycerol bound to two fatty acids and a phosphate group.

Endomembrane system

a set of membranes that form a single functional unit as being connected directly for exchanging material through vesicular transport

Polysaccharides consist of

a single kind of repeating unit, or sometimes an alternating pattern of two kinds. Repeating units of polysaccharides are monosaccharides.

cytoskeleton function

a) cell shape and internal framework b) binding sites for organelles c) cellular movement d) cellular specializations

DNA

a)double helix - 2 complementary strands of DNA; stabilized by hydrogen bonding between bases b)chromatin -DNA packaged with histone proteins 1) heterochromatin - densely coiled, less active (2) euchromatin - less dense, transcriptionally active c)most highly condensed during mitosis - forms chromosomes

Which of the following contain axoneme? (MACA) a. Cilia b. Centrioles c. Flagella d. stereocilia

a. Cilia c. flagella

Disulfide is what kind of bonding? a. Covalent bond b. Ionic Bond c. Hydrogen bond d. None of the above

a. Covalent bond

Which molecule maintains long term storage of genetic information? a. DNA b. mRNA c. rRNA d. tRNA

a. DNA

Which of the following structures are made of Microtubules? MACA a. Flagella b. Actin c. Intermediate filament d. axoneme

a. Flagella d. axoneme

Which of the following organelles is/are responsible for completion of glycosylation of glycoproteins a. Golgi complex b. rough endoplasmic reticulum c. smooth endoplasmic reticulum d. mitochondria

a. Golgi complex

Actin filaments are involved in: (MACA) a. Muscle contraction b. cleavage furrow formation c. Cytoplasmic streaming d. Mitotic Spindle

a. Muscle contraction b. cleavage furrow formation c. Cytoplasmic streaming

Fibronectin function

a. binds cells to components of extracellular matrix b. binding site for cells, collagen, heparan

Which of the following macromolecules is a polysaccharide used for structure? a. cellulose b. starch c. glucose d. glycogen

a. cellulose

Prophase

a. chromatin condenses - chromosomes become visible b. nuclear envelope breaks down c. centrosomes (pair of centrioles) separate to opposite poles d. microtubules generated connecting centrioles to chromosomes

metaphase

a. chromosomes condense further and attach to the mitotic spindle at large electron-dense protein complexes called kinetochores at each centromere b. Chromosomes are moved to align at its equatorial plane

Collagen fibers (ECM)

a. family of 25+ proteins b. Synthesis as procollagen; soluble; triple helix of 3 polypeptides c. after secreted converted tropocollagen; insoluble d. self-assembles to form fibrils and fibers

Which of the following statements regarding macromolecules is false? MACA a. it always involves polymerization of individual monomeric units b. it requires a net input of energy c. there is no directionality to the biosynthetic process d. molecules are joined together via hydration reactions

a. it always involves polymerization of individual monomeric units c. there is no directionality to the biosynthetic process d. molecules are joined together via hydration reactions

Which organelle has a highly acidic interior containing many hydrolytic enzymes? a. lysosome b. nucleus c. peroxisome d. smooth ER

a. lysosome

telophase

a. nuclear envelope regenerated b. chromosomes disperse

Laminin

a. synthesized by epithelial cells b. binds epithelia to components of basal lamina c. binding sites for collagen, heparan, cells

Steroid Hormones types

estradiol (estrogen) testosterone (anderogen) cortisol (glucocorticoid) aldosterone (mineralococorticoid)

Reticular

a. very thin fibers form loose networks b. high affinity for silver stains; argyrophilic c. found in lymphoid organs, ie. lymph nodes, spleen 3. elastic a. fiber bundles composed of elastin b. cross-linked peptides provide extensibility

Microfilaments composition

actin (1) G-actin - unpolymerized globular actin proteins (2) F-actin - filamentous actin formed by polymerization of G-actin

Centrosome

aka MTOC: Microtubule organization center for the mitotic spindle and consists of paired centrioles.

tight junction function

aka Zonula Occludens (ZO) --prevent water soluble molecules from passing through extracellular matrix between cells --fuse adjacent plasma membranes --protein strands in adjacent membranes fuse them together -maintains the polarity of the cell by restricting membrane proteins to the apical or baso/lateral surfaces --disrupted by reduction of calcium concentration

triglycerides

aka triacylglycerols consist of a glycerol molecule with three fatty acids attached to it most common in body

gap junction

allows the passage of small water-soluble molecules from cell to cell

Plasma membrane proteins are

amphipathic

Actin-linked cell-matrix junction

anchors actin filaments in cell to extracellular matrix

hemidesmosomes

anchors intermediate filaments in a cell to extracellular matrix

Reticular (type III collagen) fibers

argyrophilic

Extrinsic (peripheral) proteins

associated with either cytoplasmic or extracellular region of membrane

Peroxisomes: MACA a. Also named lysosomes b. Contain oxidases c. Contain acid phosphatases d. Breakdown long chain fatty acids

b. Contain oxidases d. Breakdown long chain fatty acids

Golgi apparatus contains ribosomes within its cisternae? a. True b. False

b. False

The site of steroid synthesis is: a. RER b. SER c. Golgi complex d. Peroxisomes

b. SER

Which of the following statements regarding macromolecules is true? a. it always involves polymerization of individual monomeric units b. it requires a net input of energy c. there is no directionality to the biosynthetic process d. molecules are joined together via hydration reactions

b. it requires a net input of energy

Which of the following cellular organelles contain hydrolytic enzymes? a. Golgi complex b. lysosomes c. Smooth Endoplasmic Reticulum d. Rough endoplasmic reticulum e. Peroxisomes

b. lysosomes

triglycerides are made of? a. two fatty acids and one glycerol molecule b. three fatty acids and one glycerol molecule c. two fatty acids plus one glycerol and one phosphate group d. none of the above

b. three fatty acids and one glycerol molecule

Adhesive glycoproteins

bind membrane proteins to collagen fibers 2 types: fibronectin & laminin

Lipids

biochemically, structurally diverse hydrophobic stable in nonpolar solvents mostly hydrocarbon chains (containing C and H) some have polar regions-amphipathic

If the nucleotide or base sequence of the DNA strand used as a template for messenger RNA synthesis is ACGTT, then what would be the sequence of bases in the corresponding mRNA? a. TGCAA b. ACGTT c. UGCAA d. GUACC

c. UGCAA

Proteins are made by polymerization of ________ a. fatty acids b. monosaccharides c. amino acids d. nucleotides

c. amino acids

Cytosine is found in? a. DNA only b. RNA only c. both DNA and RNA d. neither DNA nor RNA

c. both DNA and RNA

All of the following are examples of biological macromolecules Except: a. cellulose b. Starch c. glucose d. Hemoglobin

c. glucose

Proteins are formed by polymerization of amino acids joined together by ___________ bonds. a. glyosidic b. ionic c. peptide d. None of the above

c. peptide

Which of the following nitrogenous bases is not present in RNA? a. adenine b. cytosine c. thymine d. uracil

c. thymine

Protein Primary Structure

can be used to predict higher level protein structure

Glycolipids

carbohydrates covalently bonded to lipids determine type of cell, important for immune system

amino acids made of:

carbon atom (Chiral center) bonded to hydrogen atom amine (or amino group) variable side chain (R)

Mitosis

cell division in which the nucleus divides into nuclei containing the same number of chromosomes relatively uniform in length; 1-2 hours

Gap Junctions (Nexus)

communicating junctions --allows passage of ions and small molecules between adjacent cells --cells connected by connexons -six subunits composed of protein connexins --important in cardiac and smooth muscle allowing multiple cells to act as a single unit

Fatty acids are

components of several other kinds of lipids long amphipathic, unbranched hydrocarbon chain with a carboxyl group at one end The polar carboxyl group is the "head" and the nonpolar hydrocarbon chain is the "tail"

cytoskeleton structure

composed of 3 types of proteinaceous structures: a) microtubules b) microfilaments c) intermediate filaments

centrioles structure

composed of 9 triplets crosslinked to each other most cells have 1 pair of centrioles

Proteins are

composed of a nonrandom series of amino acids

adherenes junction

connects actin filament bundle in one cell with that in the next cell

desmosome

connects intermediate filament in one cell to those in the next cell

amino acids linked by

covalent called Peptide bond (formed between amine group of one amino acid and carboxyl group of next amino acid.

Which of the following structures does not connect the membranes of two neighboring cells? a. gap junctions b. tight junctions c. desmosomes d. Hemidesmosomes

d. Hemidesmosomes

Microtubules are not found in: a. axoneme b. stereocilia c. flagellum d. centrioles

d. centrioles

All of the following cellular structures contain microtubules except: a. cilia b. stereocilia c. flagella d. mitotic spindle

d. mitotic spindle

Apoptosis

def. = programmed cell death --kills old, damaged, infected, unneeded or otherwise abnormal cells --cells shrink, detach, round-up --release chemoattractants to stimulate phagocytosis --occurs during development --no inflammation

Cytokinesis

division of the cytoplasm A belt-like contractile ring of actin filaments forms at the end of anaphase, constriction of this ring produces a cleavage furrow and progresses until the cytoplasm and its organelles are divided into two daughter cells, each with one nucleus.

Polysaccharides function

energy storage and structural support most common energy storage form is starch (in plant cells) and glycogen (animal cells and bacteria) best-known structural polysaccharide is the cellulose found in plant cell walls --Mammals cannot digest cellulose (some have microorganisms in their digestive systems that can)

Classes of lipids

fatty acids triglycerides phospholipids glycolipids steroids Terpenes

Chromatin packing

folding and coiling DNA with the help of proteins

Ionic bonds

form between positively and negatively charged R groups

Disulfide bonds

form between the sulfur atoms of two cysteine residues (covalent bond)

Hydrogen bonds

form in water and between amino acids in a polypeptide chain via their R groups

Terpenes

formed from isoprene synthesized from the five-carbon compound isoprene and are sometimes called isoprenoids

Cilia and Flagella

hairlike structures that extend from the surface of the cell, where they assist in movement

Nucleus (Cellular regulation)

houses genetic materials, which directs all cellular activities and regulates cellular structure

Phases of the cell cycle in order

interphase (G1 = growth, S = growth and DNA synthesis, G2 = growth and final prep. for division), prophase, metaphase, anaphase, telophase, cytokinesis

microtubules structure

largest cytoskeletal elements (1) tubulin A. globular proteins B. a and b tubulin form heterodimers (2) assembly of heterodimers into protofilaments 3) protofilaments form hollow tube-like structure 4) microtubules may form as singlets, doublets, or triplets

Polysaccharides are

long chain polymers of sugars and sugar derivatives that are not informational molecules aka complex carbohydrates

Stereocilia

long tufts on top of hair cells that sway back and forth causing the opening of ion channels Hair cells are connected to the tectorial membrane and the hair cells are involved in amplifying the incoming sound

Structure of cilia and flagella

made up of two different parts: the motile cilium (upper part) and basal body (lower part ) organized into 9 pairs of microtubules with two microtubules at the center of the ring

Cholesterol

most common --Found in membrane --Regulates membrane fluidity --Involved in cellular signaling --Source of all steroid hormone

Karyokinesis (mitosis)

nuclear division

Cell Cycle

orderly progression of events in life of a cell

Interphase

period of the cell cycle between cell divisions 1. all other cellular events 2. variable in length in different cell types

terpenes can be found in

primary constituents of the essential oils of many types of plants and flowers. Essential oils are used widely as fragrances in perfumery and traditional medicine, such as aromatherapy

multimeric proteins

protein with 2 or more polypeptide chain two polypeptides are called dimers or three polypeptides are called trimers Hemoglobin is a tetramer, consisting of two alpha subunits and two beta subunits

monomeric proteins

proteins that consist of a single polypeptide

Cell cortex

reinforcing mesh of cytoskeletal elements under a plasma membrane

Macromolecules are

responsible for most of the form and order of living systems are generated by the polymerization of small organic molecules

Tight junctions

seals gap between epithelial cells

Desmosomes (Macula adherens)

similar to zonula adherens -disc shaped -cytoplasmic intermediate filaments anchor the cadherin membrane proteins (desmoglein and desmocollin) that bind the cells. It strengthens the tissue.

anaphase

sister chromatids separates and move toward the opposite pole

Ribosomes

site of protein synthesis

Nucleolus function

site of synthesis and organization of ribosomes (structures used in protein synthesis)

Cell Junctions are

specialized attachments between adjacent cells --modifications of the plasma membrane --to provide anchoring of adjacent cells to one another --to provide cytoplasmic continuity between cells

Hydrophobic interaction

the tendency of hydrophobic molecules or parts of molecules to be excluded from interactions with water

nucleic acids importance

they store, transmit, and express genetic information

Glycerol

three-carbon alcohol with a hydroxyl group on each carbon Note: Fatty acids are linked to glycerol, one at a time, by ester bonds, formed by the removal of water

Tertiary Structure def.

three-dimensional shape of a polypeptide due to interactions of the R groups of the amino acids making up the chain.

necrosis

tissue death --increase in cell volume (inflammation) --loss of plasma membrane integrity --leakage of cellular contents

Motifs are

units of secondary structure consist of short stretches of a helices and b sheets OR Certain combinations of alpha helices and beta sheets have been identified in many proteins eg. b-a-b, the hairpin loop, and the helix-turn-helix motifs

Surface Specialization Microvilli

~1μm long 1. covered with glycocalyx (sugar residues linked to membrane lipids and proteins 2. form brush (striated) border 3. found extensively on apical surfaces of absorptive cells 4. core of actin filaments arranged longitudinally 5. not motile

Fibronectin structure

•Each fibronectin subunit is folded into a series of rodlike domains •Several domains bind one or more ECM macromolecules, including several types of collagen, heparin, and fibrin •Other domains recognize and bind cell surface receptors via the RGD (arg-gly-asp) sequence

Integrins Are Cell Surface Receptors That Bind ECM Constituents

•Integrins are a large family of cell surface receptors that bind to fibronectins or laminins and collagen •Integrins integrate the cytoskeleton with the ECM •Integrins play important roles in regulating cell movement and attachment

Laminins Bind Cells to the Basal Lamina

•Laminins are found mainly in the basal lamina, a thin sheet of specialized extracellular material •It underlies epithelial cells, separating them from connective tissues

Fibronectin is involved in cell movement

•When migratory cells are grown on fibronectin, they adhere to it •In embryonic cell migration, the pathways followed by migrating cells are rich in fibronectin, suggesting it may guide the cells •Many kinds of cancer cells do not produce fibronectin