Midterm Bio Review Written Responses

What characteristics are used to determine whether something is alive or not?

All living things are composed of cells, highly organized, grow and develop, reproduce, maintain homeostasis, respond to stimuli, use/need energy and metabolize, evolve over time, based on genetic code

Are viruses living or not?

No a virus is not living because it does not have all the characteristics living organisms need to have to be considered living

Matter

Anything that occupies space and has mass

Element

A substance that can't be broken down to other substances by ordinary chemical means means

Compound

A substance consisting of two or more different elements combined in a fixed ratio

What are the 6 most common elements in living things?

Carbon. CHNOPS

Phosphorus

Sulfur

Hydrogen

Nitrogen

Oxygen

What happens during a chemical reaction?

Reactants contact each other, bonds between atoms in the reactants are broken and atoms rearrange and form new bonds to make the products

What are the components of a chemical equation?

Reactants, products, coefficients, subscripts, states

During a chemical reaction, is matter created or destroyed?

Matter is not created or destroyed but rearranged, atoms are broken apart and reformed into new substances

Adhesion

Water sticks to other things Ex. Water on a leaf

Cohesion

Water molecules “hold hands” and stick together

How is surface tension related to cohesion?

Cohesion, the attraction between like molecules is the direct cause of surface tension

Capillary action

How water moves up against gravity in plants

Capillary action is the combined result of adhesion and cohesion

How is water able to resist dramatic changes in temperature compaesd to most other substances?

Due to its high specific heat capacity

Why does ice have a lower density than liquid water?

There is more space between the water molecules to accommodate all the hydrogen bonds

So ice can float

Temperature Moderation

Takes a LOT of energy to heat water from liquid to gas(need to break the hydrogen bonds)

Water has a very high specific heat capacity

Solute

Substance that dissolves ex. Salt water

Solvent

What dissolves the solute( the liquid) ex. Water

Solution

The combination of a dissolved solute in a solvent Ex. Kool aid

What is the difference between an acid and a base?

Acid: any compound that forms a hydrogen ion in solution (pH=0-6)

Base: any compound that forms a hydroxideion in solution (pH=8-14)

What is buffer and why is it important?

A solution that resists significant oh changes when acids or bases are added, crucial for maintaining stable environments

What are the elements and monomers of carbohydrates?

Carbon, Hydrogen, Oxygen

Monosaccharides- a simple sugar like glucose and fructose

What are the 2 major functions of carbohydrates?

Structure of cells-plants only

Short term energy and storage- plants and animals

What is the relationship between monosaccharides, disaccharides, and polysaccharides?

Monosaccharides: a simple sugar like glucose and fructose( monomer of carbs)

Disaccharides: when 2 monosaccharidesdes bond together and make an energy source(dimer of carbs)

Polysaccharides: a complex carbohydrate that forms when sugars bind together in a chain, form living things, store energy( polymer of carbs)

Compare and contrast the 3 major polysaccharides with regards to structure, function, and which ogrnaims they are found in?

Starch: used to store energy in plants, some branches of glucose structure, found in plants

Glycogen: used to store energy in animals, branches of glucose structure, found in animals

Cellulose: long chains of glucose, used to form walls in plants around cells, found in plants

What are the elements and monomers of lipids?

Carbon, Hydrogen, Oxygen

Glycerol and fatty acids

Why do water and lipids not freely mix?

Lipids are hydrophobic

Describe the basic structure of fats and triglycerides?

A compound composed of a 3 carbon backbone( glycerol) and three fatty acids containing long hydrocarbons chains

List the 3 major function lipids

Triglycerides: the mainnform of stored energy in animals

Phospholipids: the major components of cell membranes

Steroids: they serve as chemical messengers

Unsaturated fats

Structure, double carbon bonds, liquid at room temp Ex. Oils

Saturated fats

Single carbon bonds, solid at room temp, Ex. Butter, lard

What are the elements and monomers of proteins?

Carbon, Hydrogen, Oxygen, Nitrogen-CHON

monomers: amino acids

What are the 4 major functions of proteins?

1. Help cells keep their share(structural proteins)

2. Make up muscle tissues

3. Transport items in and out of cells(transport proteins)

4. Some proteins act signals and other proteins receive the signals

What is a polypeptide?

A long chain of amino acids linked by peptide bonds formed through dehydration synthesis(or condensation) where water is removed and broken down via hydrolysis, which adds water to break those bonds

Why is a proteins shape important for its function?

It's shale dictates it's function/ job

What is denaturation?

Ruins the shape by unfolding the protein

Ruins function

Why are cells so small?

Volume grows faster than SA as something gets bugger small things have a high SA:v ratio, allows cells to obtain food and get rid of waster completely

How is a light microscope different from and electron microscope?

Electron microscopes produce an image of a specimen by using a beam of electrons rather than a beam of light

Electron microscopes can also produce higher- resolution images than standard light

What are the three components of cell theory?

1. All living things are composed of cells

2. Cells are the basic units of structure and function in living things

3. New cells are producuded from existing cells

Organic molecules

Carbon based molecules

An organic compounds properties depend on…

1. Size and shape of its carbon backbone

2. Atoms attached to that skeleton

What is a functional group?

A group of atoms within a molecule that interacts in predictable ways with other molecules

What is a additional characteristic that functional groups have because of their polarity?

Their polarity means they are hydrophilic and are easily soluble in water

Dehydration Reaction

Building macromolecules occurs through a dehydration reaction

Each time a monomer is added to a chain to create a polymer a water molecule is released

Acquires the assistance of an enzyme to speed up the reaction

Hydrolysis Reaction

Breaking down a macromolecules occurs through a hydrolysis reaction

eaxg time water is added to a polymer it breaks down the monomers

Requires the assistance if enzymes to help speed up the reaction

Robert Hooke

The first person to identify cells, in 1665 by using an early compound microscope by looking at a thin slide of cork(plant material)

Anton van Leeuwenhoek

Observed a sample ofnpond water using a single lens microscope- led him to discover a world of tiny living organisms

Matthias Schleiden

1838: German Botanist, concluded that all plants are made of cells

Theodore Schwann

1839: German scientist, concluded that all animals are made of cells

Rudolf Virchow

1855m German physician, summarized that cells come from preexisting cells

Prokaryotic cell

No nucleus

No membrane bound organelles

Smaller

Simple

Ex. Bacteria

Eukaryotic cell

Has a nucleus

Has membrane bound organelles

Larger

Complex build

Ex. Plants, animals, fungi, protists

How are prokaryotic and eukaryotic cells similar?

Both have cytoplasm, cell membrane, ribosomes, DNA

What is an organelle?

A specialized membrane-bond structure inside a cell that performs a specific job

What are similarities and differences between plant and animal cells?

Plant: cell wall and cell membrane, large central vacuole, chloroplasts, performs photosynthesis to create their own food

Animal: cell membrane, no cell wall, no chloroplasts, often small, temporary vacuoles, centriols

Similar: both have cytoplasm, cell membrane, nucleus, ER, Golgi Apparatus, ribosomes

Chloroplasts

Converts sun energy into usable energy for the plant cell

Mitochondria

Produce and convert energy

Golgi apparatus

Packages proteins and lipids for transport

Nucleus

Control center/DNA storage

Rough ER

Synthesizes and modified proteins/ has ribosomes

Smooth ER

Makes lipids and detoxifies the cell

Vacuole

Storage and waster removal

Organic molecules

Carbon-based molecules Ex. Chloroform, acetone, acetic acid

Monomers

Single molecule, building block of carbon molecules ex. One train car

Polymers

Three or more monomers bonded together Ex. Entire train

What are the 2 major functions of the cell membrane

Regulates what enters and leaves the cell

Provides protection and support

Why is the cell membrane is described as a fluid mosaic model

It is a fluid structure with a mosaic pattern of various components

Hydrophobic

Repels ans is repelled by water, inner portion of cell membrane

No contact with liquid environment

Hydrophilic

Attracted to water, outer portion of cell membrane

Comes into contact with liquid environment

What is the function of cholesterol in cell membranes

To regulate membrane flexibility by preventing phospholipids from packing too tightly(making it less fluid at higher temps) and keeping them from sperating too much(allowing fludity at lower temperatures)

List 2 functions of membrane proteins

1. Transporting substances across the cell membrane(ions and nutrients)

2. Provide structural support

Why is the cell membrane described as being selectively permeable

Only allows certain substances to pass

Cross with ease: nonpolar molecules ex. O2, CO 2

Unable to cross: polar molecules and many ions ex. Sugar

Water is a exception and is able to cross

Define the term concentration gradient

The difference is concentration across a space

Connect the terms solution, solute, and solvent

A solvent dissolves the solute= the solution

What is diffusion

The passive movements of molecules from a high to low concentration till equilibrium is reached, so the cell can maintain homeostasis

How is active transport different from oassive transport

Moves against concentration gradient

Moves from low to high concentration

Osmosis

Passive diffusion of water across a selectively permeable membrane from a high to low concentration

Hypertonic

High concentration of water at start: inside the cell

Low concentration of water: outside the cell

Water will flow out of the cell

Animal cell: shrinks and shriveled up b/c no cell wall

Plant cell: shrinks on the inside b/c of the cell wall

Hypotonic solution

High concentration of water at start: outside the cell

Low concentration of water at start: inside the cell

Water will flow into the cell

Animal cell will: expand and/or burst b/c no cell wall

Plant cell will: fill with water but does not burst b/c of the cell wall

Isotonic solution

Concentration of water and solutes is the same inside and outside the cell

Water will flow into and out of the cell at a equal rate(no net change)

Nothing will happen to animal or plant cell

How does osmosis affect plant and animal cells differently

Plant cells have a rigid cell wall while animal cells do not leading to varies responses in hypotonic and hypertonic environments

Differentiate between facilitated diffusion and active transport

Facilitated: moves molecules and ions across the cell membrane through the use of transport proteins(carrier +channel) occurs from high concentration to low concentration

Active: moves larger molecules across the cell membrane through a transport protein(usually) from low to high concentration using energy from molecules of ATP

How do endocytosis and excytosis differ from one another

Endocytosis: membrane surrounds the particle to pull it INTO the cell by enclosing it in a vesicle

Vesicle is made from the membrane

Exocytosis: a vesicle is moved to the plasma membrane and material is pushed OUT of a cell

Removes waste

Distributes molecules made in cell

Phagocytosis

Moves solid food or whole cells INTO cell

Pinocytosis

Moves liquid droplets (nutrients dissolved in solution) INTO cell

Define homeostasis and discuss it's importance to cells

Maintains a stable internal environment, cells need these conditions to function, grow, get energy, and survive

Aquaporins

Protein channels in cell membranes that provide rapid, selective pathways, for water molecules dramatically speeding up osmosis

Energy

The ability to cause change in the form of work

How do exergonic and endergonic reactions differ

Exergonic: energy being released

Endocytosis: energy being stored (in products)

What is ATP

Energy- adenosine triphosphate

How is the energy of ATP stored? How is it released?

Stored in the high energy chemical binds between it's three phosphate groups

Released by breaking the bond between it's second and third phosphate groups through hydrolysis

The 3 types of cellular work

What does it mean to say that an enzyme is a catalyst

Enzymes speed up chemical reactions in living things wihtihr being used up or permanently changed in the process

What is meant the term induced fit in connection to enzymes

Flexible proteins who active sites change shape upon substrate binding, creating a good fit

How can changes in pH and temperature affect enzyme activity

Cells and tissues(groups of cells with the same function) are only able to survive in a narrow pH range around 7 in most areas of the body. Going outside of this range will cause cells to lose their functionality due to their dependence on proteins and enzymes these would become denatured

What is a inhibitor

A substance or molecule that stops or slows down a specific chemical reaction

Differentiate between competitive inhibition and non-competitive inhibition inhib

Competitive inhibitors= chemical/ compounds that resemble an enzymes normal substrate and they compete for access to an enzymes active site. If successful, they block the substrate from the active site and decrease a enzymes productivity

Non-competitive inhibitor= chemicals/compounds that bind to a site elsehwre on the enzyme, which causes the active site to change shape. This prevents the substrate from being able to bind as it shape does not the active site; the enzyme is no longer able to properly function

Cellular respiration

The process that releases energy by breaking down glucose and other food molecules in the presence of oxygen

Balanced chemical equation for cellular respiration

C6 H13 O6+ 6O2= 6 CO2+ 6 H2O+ ATP

Glycolysis

1. Prep glucose for the Krebs cycle by breaking it in half into 2 small, er pyruvate molecules

2. Generates NADH to help transfer electrons to the ETC

   location:cytoplasm