Ch. 1 (Cells)

Whare are the 3 types of membrane proteins?

1. peipheral
2. integral
3. transmembrane

Which **membrane** **proteins** provide a passageway through the membrane for hydrophilic, polar, and charged substances?

channel proteins

Which **membrane proteins** are a type of glycoprotein that distinguish between self and foreign substances?

recognition proteins (note: MHC on macrophage)

Which **membrane proteins** are used to pass ions across the membrane and referred to as gated channels in nerve and muscle cells?

ion channels

What are the types of **ion channels**?

1. voltage-gated
2. ligand-gated
3. mechanically gated

Which **membrane proteins** allow the passage of certain ions and small polar molecules, are less specific, and create relatively large openings?

porins

Which **membrane proteins** are specific to movement across the membrane via integral membrane proteins?

carrier proteins

How do carrier proteins allow **specific** **molecules** to pass across the membrane?

changes shape after binding to specific molecule

Which **membrane proteins** can use ATP to transport materials across the membrane?

transport proteins (note: includes active transport and facilitated transport)

What is the **difference** between active transport and facilitated diffusion?

active transport requires energy and facilitated diffusion does not

Which **membrane** **proteins** attach cells to neighboring cells and provide anchors for stability via internal filaments and tubules?

adhesion proteins

Which **membrane proteins** serve as binding sites for hormones and other trigger molecules?

receptor proteins

Which **membrane property** allows small uncharged molecules to cross the cell membrane?

phospholipid membrane \n semi permeability (note: all other substances \n require a transporter)

Which **membrane component** maintains membrane integrity over a range of temperatures?

cholestrol (note: sterols perform similar functions in plants)

What do prokaryotic cells **use** **instead** of cholesterol in their membrane?

hopanoids

Which **membrane** **component** makes a carbohydrate coat that covers the cell wall of some bacteria and the plasma membrane of some animal cells?

glycocalyx

What are the **components** of the glycocalyx?

1. glycolipids attached to the plasma membrane
2. glycoproteins serving as recognition proteins

What are the **functions** of the glycocalyx?

1\. adhesion \n 2. barrier to infection \n 3. markers for \n cell-cell recognition

Which **organelle** contains chromatin, which is the general packaging structure of DNA around proteins in eukaryotes?

nucleus

What are **tightly** **condensed** **chromatin** when the cell is ready to divide?

chromosomes

What **structures** serve to organize DNA which coil around it into bundles called nucleosomes?

histones

Nucleosomes are wrapped around **what** **number** of histone proteins?

8

Which **structure** is located inside the nucleus and serves as the site of ribosome synthesis?

nucleolus

What **organelles** are synthesized using rRNA and proteins which are imported from the cytoplasm?

ribosomes

What is the **double**-**layered** **boundary** that binds the nucleus?

nuclear envelope

What **structures** allow transport across the nuclear envelope?

nuclear pores

What is the cytoplasm-like **substance** within the nucleus?

nucleoplasm

What is a dense fibrillar **network** inside of the nucleus of eukaryotic cells?

nuclear lamina

What are the **components** of the nuclear lamina?

1. intermediate filaments
2. membrane-associated proteins

What are the **functions** of the nuclear lamina?

1\. mechanical support \n 2. regulation of DNA replication, cell division, and chromatin organization

Which **organelle** is the irregular shaped region within prokaryote cells that contains all or most of the cell’s genetic material?

nucleoid

What is the **area** that contains the cell’s metabolic activity and transportation (cytosol and organelles)?

cytoplasm

The **streaming** **movement** within the cytoplasm?

cytoplasmic streaming

What is cytoplasm **minus** suspended structures?

cytosol

What are **organelles** made of rRNA that function to make proteins?

ribosomes

How many **subunits** make up ribosomes?

60S + 40S = **80S**

Which **ribosomal** **subunits** are particular to the prokaryotic cell?

50S+ 30S = **70S**

Which **organelle** is a network of membranous tubules within the cytoplasm of a eukaryotic cell that is continuous with the nuclear membrane?

ER

Which **endoplasmic** **reticulum** is studded with ribosomes and creates glycoproteins by attaching polysaccharides to polypeptides?

rough ER

Which **endoplasmic** **reticulum** has no ribosomes and synthesizes lipids and steroid hormones for support?

smooth ER

How does the **smooth** **ER** in the liver differ compared to other locations?

liver's smooth ER breaks down toxins, drugs, and toxic by-products from cellular reactions

What is smooth and striated muscles' **ER** called?

sarcoplasmic reticulum

What is the **function** of sarcoplasmic reticulum?

store and release ions like Ca2+

Which **organelle** is a vesicle produced from the Golgi that contains digestive enzymes with low pH?

lysosomes

What is the **function** of lysosomes?

1\. apoptosis \n 2. break down \n nutrients, bacteria, \n and cell debris

What is the relative **pH** of lysosomes?

low

Which **organelle** transports various substances in vesicles and has flattened sacs known as cisternae?

golgi

Which **vesicles** are associated with the cis face of the golgi?

incoming vesicles

Which **vesicles** are associated with the trans face of the golgi?

secretory vesicles

Which **organelle** is common to the liver and kidney and breaks down substances, fatty acids, and amino acids?

peroxisomes (note: general reacition - H2O2 + RH2 → R + 2H2O)

In which **type of cells** do peroxisomes modify by-products of photorespiration?

plant cells

What is the **name** of peroxisomes in germinating plant seeds?

glyoxysomes (note: break down stored fatty acids to fuel growth)

What do **peroxisomes** produce to oxidize substrates?

H2O2

Which **organelles** are made up of the protein, tubulin and provide support and motility for cellular activities?

microtubules

During cell division, what **structure** do microtubules act as to guide chromosomes?

spindle apparatus

What is the **arrangement** of microtubules in the flagella/cilia of animal cells and lower plants (moss/ferns)?

9+2 array

Which **organelle** provides support for maintaining cell shape (ex: keratin)?

intermediate filament

Which **organelle** is made of actin and involved in cell motility; found in skeletal muscle, amoeba pseudopod, and cleavage furrows?

microfilament

Which **organelle** includes centrioles and basal bodies, are found at the base of each flagellum and cilium, and organize their development?

microtubule organizing center (MTOC)

What is the **arrangement** of MTOCs?

9x3

Which **organelle** moves materials between organelles or between organelles and the plasma membranes?

transport vacuole

Which **organelle** acts as a temporary receptacles of nutrients that merge with the lysosomes in order to breakdown food?

food vacuole

Which **organelle** is large and occupies most of the plant cell's interior?

central vacuole

What is the **function** of the central vacuole?

1\. maintain rigidity \n 2. apoptosis \n 3. break down nutrients, bacteria, and cell debris

How does the central vacuole maintain **rigidity** in a plant cell?

exert turgor when fully filled

What is the central vacuole's specialized **membrane**?

tonoplast

Which **organelle** stores starch, pigments, and toxic substances such as nicotine?

storage vacuole

Which **organelle** functions to collect and pump excess water out of the cell via active transport to prevent bursting in protists?

contractile vacuole

Which **organelle** functions to provide a perimeter of support in plants, fungi, protists, and bacteria?

cell wall

What **substance** composes plant cell walls?

cellulose

What **substance** composes fungal cell walls?

chitin

What **substance** composes bacteria cell walls?

peptidoglycan

What **substance** composes archaean cell walls?

polysaccharides

What **substance** is between adjacent cells and contains fibrous structural proteins, adhesion proteins, and polysaccharides?

extracellular matrix

What is the **function** of extracellular matrix?

1\. provide mechanical support \n 2. help bind adjacent cells \n 3. help transmit chemical/mechanical signals

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What are the common **proteins** that binds adjacent cells?

1\. collagen (most common) \n 2. integrin \n 3. fibronectin

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What are the ways cells **adhere** to the extracellular matrix?

1. focal adhesions
2. hemidesmosomes

What **connections** do focal adhesions create?

ECM to actin filaments

What **connections** do hemidesmosomes create?

ECM to intermediate filaments

Which **organelle** includes chloroplasts, leucoplasts, and chromoplasts?

plastids

Which plant **organelle** is the site of photosynthesis?

chloroplast

Which plant **organelle** specializes to store starch, lipids, and proteins as amyloplasts, elaioplasts, and proteinoplasts, respectively?

leucoplast

Which plant organelle stores carotenoids?

chromoplast

Which **organelle** is double-layered, makes ATP, and performs beta-oxidation of fatty acids?

mitochondria

What **shape** is the DNA of mitochondria?

circular

Which protein making **organelle** are contained within mitochondria?

ribosomes

Which eukaryotic **matrix** includes microtubules, microfilaments, intermediate filaments, aids in cell division, and organelle/cytoplasm movement?

cytoskeleton

What action does the plant vacuole take take in a hypotonic environment?

swells

What **state** does a plant cell take in an isotonic environment?

flaccid

What **occurs** in a plant cell in a hypertonic environment?

plasmolysis

What **occurs** in an animal cell in a hypotonic environment?

cytolysis

What is the **network** **of** **organelles** and structures, either directly or indirectly connected that transport proteins and other macromolecules into or out of the cell?

endomembrane system

Which organelles compose the endomembrane system?

1\. plasma membrane \n 2. ER \n 3. Golgi \n 4. nuclear envelope \n 5. lysosomes \n 6. vacuoles \n 7. vesicles \n 8. endosomes

Which **mobility** **structure** undulates like a snake?

flagella

Which **mobility** **structure** beats in a rapid back and forth pattern?

cilia

What are the two **methods** of circulation throughout the cell?

1\. intracellular \n 2. extracellular

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Which **method** of cell circulation involves Brownian movement?

intracellular

Which **method** of cell circulation involves circular motion of cytoplasm around cell transport molecules (cyclosis/streaming)?

intracellular

In intracellular cell circulation, which **organelle** provides a channel from the nuclear membrane to the plasma membrane?

ER

Which **method** of cell circulation employs diffusion?

extraceullar