Bio-101 Exam 2!

Test is 3/30

The objective of cellular respiration is to ________, which makes it a(n) __________ reaction

break down glucose….catabolic

The first step in cellular respiration is _________, which is the process of splitting glucose into two molecules

glycolysis

If oxygen is present, which membranous organelle will the cell use to obtain further energy from glucose?

Mitochondrion

If oxygen is not present, most animal cells will convert pyruvate into _________.

lactic acid

If oxygen is not presnt, yeast will convert pyruvate into __________.

ethanol

If oxygen is not present, some bacteria will convert pyruvate into _______, which is how we get some food products like yogurt or sauerkraut.

lactic acid

Which process results in the most ATP production?

Electron transport chain

If the cell is using _______ for cellular respiration, its glycerol heads will start with glycolysis while the fatty acid tails will be converted to Acetyl Co-A

Lipids

The cell can use proteins for energy via aerobic cellular respiration; however, _________ is a dangerous by-product

ammonia

In addition to ATP, cellular respiration produces ____________

carbon dioxide and water

Cellular respiration equation

Aerobic Respiration Summary

• break down glucose

• releases CO2

• lots of ATP produced

• catabolic/exergonic

Aerobic Respiration:

Stage 1

Glycolysis (Anaerobic)

• glucose split into 2 pyruvates

• occurs in cytosol

• produces 4 atp/uses 2 atp

Aerobic Respiration:

Stage 2

Krebs cycle/citric cycle (anaerobic)

• occurs in mitochondria

• produces 2 atp

• releases CO2

Aerobic Respiration:

Stage 3

Electron transport phosphorylation (aerobic)

• stepwise flow of electrons

• occurs in mitochondria

• oxygen is the final acceptor of electrons and hydrogen

• produces 32 atp

Anaerobic respiration:

Fermentation - lactic acid

• animals/bacteria

• glycolysis occurs as normal

• pyruvate is converted into lactate

• carbon dioxide released

Anaerobic respiration:

Fermentation - alcohol

• yeast

• glycolysis occurs as normal

• pyruvate is converted into acetaldehyde

• acetaldehyde is converted into ethanol

• carbon dioxide is released

Energy can be potential or kinetic. __________ is an example of potential energy, while ________ is an example of kinetic energy.

The energy stores in a chemical molecule or bond…. heat

“Energy can be neither created nor destroyed” is a part of the ______?

First Law of Thermodynamics

All biological reactions require energy. The amount of energy required to start a reaction is called ________. If there is more energy released than required, the reaction is _________. If energy is not released from the reaction, it is ________.

activation…exergonic…endergonic

Enzymes are catalysts, meaning they speed up reactions. They work by lowering the _______.

activation energy

Exergonic vs. endergonic

Photosynthesis diagram

Cellular respiration 4 steps

1) glycolysis

2) prep reaction

3) citric acid cycle

4) electron transport chain and chemosis

Did the germinating beans perform photosynthesis or cellular respiration?

Cellular respiration

Did spinach leaves perform photosynthesis or cellular respiration?

Photosynthesis

The two organelles that produce energy in plant and animal cells are:

chloroplast and mitochondria

In photosynthesis, which process is used to generate ATP?

light dependent reaction

What are the by-products of the Calvin cycle?

glucose and water

In cellular respiration, which step produces the majority of ATP?

Electron transport chain and chemiosis

Why must oxygen be present for the electron transport chain to function?

Oxygen accepts electrons to keep them moving through the chain

Regulates what enters and exits the cell; selective permeability

Cell membrane

Supports and protects plant cells; made of cellulose

Cell Wall

Site of photosynthesis

Chloroplast

Fluid inside the cell where organelles are suspended

Cytoplasm

Network of membranes that transport materials

• lipid synthesis; protein processing

Key features: Rough version has ribosomes and makes proteins, smooth version lacks ribosomes, makes lipids, and detoxifies

Endoplasmic reticulum (E.R.)

Modifies, sorts, and packages proteins for transport

• packaging and vesicle formation

Key features: stack of membrane stacks

Golgi apparatus

breaks down waste and cellular debris; apoptosis

• digestion

Key features: contain digestive enzymes; involved in apoptosis

Lysosome

Controls cell activities; contains DNA; RNA synthesis

Key features: envelope, nucleolus, chromatin; double membrane

Nucleus

Produces ATP (energy) through cellular respiration

Mitochondrion

Site of protein synthesis

Ribosome

Kinetic energy

energy in motion

• light

• heat

• electricity

• mechanical

potential energy

stored energy

• chemical

• position

First Law of Thermodynamics

Energy can not be created nor destroyed; Energy can be transferred and transformed

Second Law of Thermodynamics

With energy transfer, entropy (randomness) increases

Metabolism

sum of all chemical reactions

Exergonic

energy out (free energy)

Endergonic

energy in (energy required)

Activation energy

Energy required to start a reaction

Enzyme

biological catalyst that speed up reactions by lowering activation energy

Examples of enzymes

Lactase (Lactose)

Amylase (Strach)

Pepsin (“Meat”)

Lock and key model: Enzyme

Active site

specific to certain enzymes

Endocytosis

Bringing solutions/particles into a cell via vesicles (e.g. Pinocytosis & Phagocytosis)

Exocytosis

Moving solutions or molecules out of a cell (e.g. secretions) by packaging things into vesicles that fuse with the membrane before exiting the cell

Membrane Structure and Function:

Plasma Membrane

• selectively isolates the cell’s contents

• regulates exchange of substances

• Communication with other cells

Membrane Structure and Function:

Phospholipids

fluid-like properties; regulation

Membrane Structure and Function:

Transport proteins

moves molecules across the membrane

• channel - molecules pass through

• carrier - molecules helped through

Membrane Structure and Function:

Peripheral proteins

“docking sites”; recognition

Membrane Structure and Function:

Carbohydrates

recognition

Membrane Structure and Function:

Cholesterol

stabilizes; allows flexibility

Membrane-Crossing Mechanisms:

Passive Transport

• Diffusion - Movement from area of high to low concentration

• Osmosis - Diffusion of water

Membrane-Crossing Mechanisms:

Energy-Required

• Active transport - moving through protein, but requires energy

• Endocytosis - 2 types; water is pinocytosis and food is phagocytosis

• Exocytosis

Solvent

The liquid that dissolves the solute

Ex - water, fats, and oils

Solute

Solid that is dissolved in the liquid (solvent)

Ex - simple sugars, proteins/amino acids, salts

Tonicity

Amount of solute dissolved in solution

Hypertonic

More solute (solid) by comparison

Isotonic

Equal solute

Hypotonic

less solute (solid) by comparison

Tonicity diagram

Peroxisomes

Break down fatty acids and detoxify harmful byproducts

Key features: Contain oxidative enzymes; distinct from lysosomes

Vacuoles

Storage of water, ions, and waste; maintain turgor pressure in plants

Key features: Large central vacuole in plant cells; small, temporary vacuoles in animal cells

the smallest structure capable of performing all the necessary functions for life

cell

cell theory

1. All organisms are composed of cells.

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

3. Cells come only from preexisting cells because cells are self-reproducing.

cells without a nucleus

prokaryotic

cells that have a nucleus

eukaryotic

Two of the three domains of life, the Eubacteria and Archaea, are ________ cells.

prokaryotic

Phospholipid heads are…

hydrophilic

Phospholipid tails are..

hydrophobic

The term selectively permeable means that…..

certain substances can move across the membrane while others may not

An animal cell in a _________ solution may lyse or burst open

hypotonic

An animal cell in a ___________ solution will shrivel up or crenate

hypertonic