Biology 1801 Test 2- John Walker (AppState)

What are vacuoles?

large, membrane-bound structures found in plants and fungi

What are some functions of vacuoles?

Some are specialized for digestion, Most are used to store water and ions to help the cell maintain it normal volume- (turgor pressure), May contain pigments, & noxious compounds

Do plant cells have cell walls?

Yes

What are peroxisomes?

Little membrane-bound sphere

What are peroxisomes involved in?

Oxidation reactions (remove electrons) and production of free radicals

Where do peroxisomes originate from?

Buds from the ER

Oxidation often produces what?

Hydrogen peroxide

In peroxisomes, the enzyme catalase ________ it?

detoxifies

What do the mitochondria supply to the cells?

ATP

How many membranes does a mitochondria have?

2 membranes

The inner membrane is folded into a series of sac-like ______ in a mitochondria?

cristae

What is the solution inside the inner membrane of a mitochondria called?

Mitochondrial matrix

The space between the membranes in a mitochondria is called?

Inter-membrane space

Mitochondria have their own DNA called?

mtDNA

What do mitochondria manufacture their own of?

ribosomes

Most plant and algal cells have chloroplasts, where __________ takes place?

photosynthesis

How many membranes does a chloroplast have?

3 membranes

Innermost membrane contains flattened sacs called what?

thylakoids

Internal compartment in a chloroplast is called?

Thylakoid Lumen

Thylakoids are arranged in stacks called

grana

What surrounds the thylakoids ?

Stroma

What two things do chloroplasts do on their own?

Contain their own DNA and manufacture their own ribosomes

What is the endosymbiosis Theory

Bacteria were engulfed and a mutually beneficial relationship evolved

Evidence for the endosymbiosis theory

1. Mitochondria and chloroplasts contain their own DNA
2. Synthesize their own small ribosomes
3. Grow and divide independently of cell division
4. Phylogenetic relationship to free living bacteria

What is the cytoskeleton composed of?

protein fibers

What does the cytoskeleton give cells?

Their shape and structural ability

What things does the cytoskeleton do?

1. Aids cell movement
2. Transports materials within the cell
3. Organizes the organelles and other cellular structures into a cohesive whole

Which type of cell requires an abundance of mitochondria?

A) Plant Leaf Cell
B) Animal Pancreatic Cell
C) Animal Testes Cell
D) Animal Muscle Cell

Answer- D

Your body's cells use and synthesize approximately ________ ATP molecules per second

10 million

Cellular enzymes can catalyze more than ______ reactions per second

25,000

Each membrane ________ can travel the breadth of its organelle or cell in under a minute

phospholipid

_____________ of mitochondria are completely replaced about every 10 days

Hundreds of trillions

Exocytosis

Export of a substance out of a cell by formation of a membrane-bound vesicle

Lysosomes digest large molecules so ___________ can be used/recycled

monomers

Endocytosis

Materials are brought into the cell by pinching off the plasma membrane

Examples of endocytosis

1. Receptor-mediated endocytosis
2. Phagocytosis - engulfing large particles, bacteria etc.

What are the three types of cytoskeleton elements?

actin filaments, intermediate filaments, and microtubules

Actin Filaments

Smallest, formed from actins, two twisted strands
Interacts with myosin (motor protein)
Cell shape, movement

Intermediate Filaments

1. Provide structural support for the cell
2. Nuclear lamins Give the nucleus its shape and organize chromosomes

Microtubules

1. Largest, tubular and is composed of tubulin
2. Provide a structural framework for organelles
3. Are involved in movement Separate chromosomes during cell division and serves as "railroad tracks" for vesicle transport

Which cytoskeletal element is involved directly in muscle contraction?

Actin

Cells produce ______________ of distinct proteins

tens of thousands

8 vital, tremendously versatile components of cells

1. Hair and Nails
2. Blood
3. Brain and nerves
4. Enzymes
5. Cellular construction workers
6. Muscles
7. Cellular messengers
8. Antibodies

Parts of Amino Acid: central C, amino, carboxyl, residue or side chain

The properties of amino acids are determined by their _________

R-groups

Side chains can be grouped into what three types?

1. Charged—includes both acidic (-) and basic (+)
2. Uncharged polar
3. Uncharged non-polar

Charged and polar side chains are hydrophilic or hydrophobic: They interact readily with water

Hydrophilic

Non-polar side chains are hydrophobic or hydrophilic: They do not interact with water

Hydrophobic

There are 20 common amino acids. The distinguishing feature that makes each one unique is?

The nature of the R-group

Are proteins macromolecules?

Yes

Macromolecules are large molecules made of smaller subunits
Subunits are called _______ ("one-part")
Monomers link together (polymerize) to form ________ ("many-parts")

monomers, polymers

Amino acids are the __________ that make up proteins

monomers

Monomers polymerize through _______________, which results in the loss of a water molecule and hydrolysis is the inverse reaction

condensation (dehydration synthesis) reactions

Dehydration reaction is a type of ___________ reaction.

condensation

Amino acids ________ when a bond forms between a ________ group of one amino acid and an _________ group of another

polymerize, carboxyl, amino

The resulting C-N bond is called a?

peptide bond

Peptide bonds are formed by hydrolysis

False

Peptide bonds form a "backbone" with?

1. R-group orientation
2. Directionality
3. Flexibility

A chain of many amino acids is a ___________ ("many-peptides")

polypeptide

___________ are the complete, functional form of the molecule

Proteins

What do proteins look like?

unparalleled diversity of size, shape, and chemical properties

Proteins have just four basic structures:

1. Primary
2. Secondary
3. Tertiary
4. Quaternary

Protein _______ _______ is its unique sequence of amino acids

primary structure

The amino acid ___________ affect a polypeptide's properties and function

R-groups

A single amino acid change can radically alter ________ function

protein

Protein secondary structure is formed by ________ bonds between certain amino acids (carbonyl group - amino group)

hydrogen

2 Types of secondary structure in proteins

1. α-helices
2. β-pleated sheets

Which level of protein structure includes α-helices & β-pleated sheets?

Secondary structure

The tertiary structure of a polypeptide results from?

1. Interactions between R-groups
2. Or between R-groups and the peptide backbone
3. Bending and folding contribute to the distinctive three-dimensional shape of the polypeptide

Five important types of R-group interactions:

1. Hydrogen bonds
​2. Hydrophobic interactions
​3. Van der Waals interactions—weak electrical interactions between hydrophobic side chains
​4. Covalent disulfide bonds—form bridges between two sulfhydryl groups
5. ​Ionic bonds

The bonding of two or more distinct polypeptide subunits produces _______________

quaternary structure

Some cells contain _______________ - Groups of multiple proteins that carry out a particular function

molecular machines

The bonding of two or more distinct polypeptide subunits produces which level of structure?

Quaternary

Protein folding is often spontaneous or non-spontaneous?

spontaneous

Proteins called __________ help proteins fold correctly in cells

molecular chaperones

A ____________ (unfolded) protein is unable to function normally

denatured

__________ in proteins can be "infectious"

Misfolding

________ are improperly folded forms of normal proteins

Prions

__________ may be the most important protein function

Catalysis

An _________ is a protein that functions as a catalyst

enzyme

The location on an enzyme where substrates bind and react is the?

active site