BIO Exam Review 2 Flashcards

Questions and Answers

Which of the following does not support the endosymbiotic theory?

Contains bacteria-like ribosomes

Are both double membrane bound

Have the same sizes (correct)

Contain their own DNA

Which of the following characteristics is NOT shared by bacteria and archaea?

Absence of nuclear membrane

Identical cell wall composition (correct)

Presence of plasma membrane

Presence of ribosomes

Why do enzymes released from the lysosome become inactive in the cytosol?

Cytosolic pH is near-neutral, and the enzymes require a low pH to function.

What are some parts of the endomembrane system?

Golgi apparatus, vacuole, endoplasmic reticulum, lysosomes, nuclear membrane Signup and view all the answers

What is the general pathway for a newly synthesized protein that will be secreted by the cell?

Endoplasmic reticulum, Golgi apparatus, vesicles moving to plasma membrane Signup and view all the answers

How were some antibiotics made to target microbes and not the eukaryotic host?

Prokaryotes have ribosomal subunits that differ from eukaryotes. Signup and view all the answers

NAD+ is the _ form of NADH while NADH is the _ form of NAD+.

oxidized; reduced Signup and view all the answers

What is the source of energy during the energy investment phase of glycolysis?

ATP Signup and view all the answers

What is the substrate for the first step in glycolysis?

Glucose Signup and view all the answers

In the generic redox reaction: A + B --> C + D, what occurs?

One substrate gains an electron while the other loses an electron. Signup and view all the answers

During respiration, what happens as electrons are passed through the electron transport chain?

The energy released is used to actively pump H+ ions across a membrane to form a proton gradient. Signup and view all the answers

In a eukaryotic cell, where does electron transport take place?

The inner mitochondrial membrane Signup and view all the answers

What is the endosymbiotic theory in a nutshell?

Nonphotosynthetic cells engulf photosynthetic cells as well as mitochondria. Signup and view all the answers

What are peroxisomes?

Specialized metabolic compartments bounded by a single membrane. Signup and view all the answers

What is the 'skeleton' of the cell?

Cytoskeleton Signup and view all the answers

What are the functions of the cytoskeleton?

Gives shape and movement, anchors many organelles, vesicles travel along tracks. Signup and view all the answers

What is the thickest component of the cytoskeleton?

Microtubules Signup and view all the answers

What is the thinnest component of the cytoskeleton?

Microfilaments (actin) Signup and view all the answers

What is the arrangement of microtubules?

9 doublets surrounding 2 singlets Signup and view all the answers

What are plasmodesmata?

Channels through cell walls that connect the cytoplasms of adjacent cells. Signup and view all the answers

What are tight junctions?

Membranes of neighboring cells are pressed together, preventing leakage of extracellular fluid. Signup and view all the answers

The main electrogenic pump in plants, fungi, and bacteria is the _ pump, which transports hydrogen ions out of the cell. The pumping of hydrogen ions transfers a __ charge from the cytoplasm to the extracellular fluid.

proton; positive Signup and view all the answers

On the basis of energy requirement, which does not belong to this group?

Active transport Signup and view all the answers

Which of the following does not exemplify exocytosis?

Formation of new vesicles from the plasma membrane Signup and view all the answers

Which of the following statements is false?

Integral proteins may extend only partway into the hydrophobic interior Signup and view all the answers

Which of the following is NOT an example of facilitated diffusion?

Electrogenic pump Signup and view all the answers

Which does not describe a biological membrane?

Its protein and lipid components are symmetrically distributed. Signup and view all the answers

Study Notes

Endosymbiotic Theory

Chloroplasts and mitochondria share features supporting the endosymbiotic theory, such as possessing their own DNA and being double membrane-bound.
The incorrect assertion that chloroplasts and mitochondria have the same sizes does not support the theory.

Bacteria and Archaea

Shared characteristics include the presence of a plasma membrane and absence of a nuclear membrane.
Bacteria and archaea differ in cell wall composition, with a unique composition distinguishing them.

Enzyme Activity and Lysosomes

Enzymes released from lysosomes become inactive in the cytosol due to the near-neutral pH, which is not optimal for their function requiring a low pH.

Endomembrane System Components

Key components include the Golgi apparatus, vacuole, endoplasmic reticulum, lysosomes, and nuclear membrane.

Protein Secretion Pathway

Newly synthesized proteins are directed from the endoplasmic reticulum to the Golgi apparatus, followed by vesicular transport to the plasma membrane.

Antibiotics and Ribosomal Differences

Antibiotics target prokaryotic ribosomal subunits that differ from eukaryotic ribosomal structures, allowing for selective inhibition of peptide formation.

NAD+ and NADH

NAD+ is the oxidized form, while NADH is the reduced form of NAD+.

Glycolysis Energy Requirements

The energy investment phase of glycolysis relies on ATP as the source of energy.

Glycolysis Substrate

Glucose serves as the substrate during the initial step of glycolysis.

Redox Reactions

In a redox reaction, one substrate gains an electron while another loses an electron.

Electron Transport Chain Function

Energy released during electron transport is used to pump H+ ions across a membrane, creating a proton gradient.

Electron Transport Location

In eukaryotic cells, electron transport occurs within the inner mitochondrial membrane.

Overview of Endosymbiotic Theory

Endosymbiotic theory posits that a nonphotosynthetic cell engulfed photosynthetic cells along with mitochondria, suggesting a symbiotic relationship.

Peroxisomes

Peroxisomes are specialized metabolic compartments with a single membrane, involved in hydrogen peroxide production and its conversion to water, with relationships to other organelles largely unexplored.

Cytoskeleton Functions

The cytoskeleton offers structural shape, facilitates movement, anchors organelles, and serves as tracks for vesicular transport.

Cytoskeleton Components

Microtubules are the thickest component, while microfilaments, also known as actin, are the thinnest component.
Microtubules are arranged in a structure of 9 doublets surrounding 2 singlets.

Cellular Junctions

Plasmodesmata are channels connecting cytoplasms of adjacent plant cells.
Tight junctions involve membranes pressed together to prevent leakage of extracellular fluid.

Electrogenic Pump in Cells

The proton pump is the main electrogenic pump in plants, fungi, and bacteria, transporting hydrogen ions out of the cell, creating a positive charge in the extracellular fluid.

Transport Mechanisms

Active transport is distinct from passive transport, facilitated diffusion, and osmosis based on energy requirements.

Exocytosis Examples

Exocytosis refers to the delivery of proteins and carbohydrates from Golgi vesicles to the outside of cells, including neurotransmitter release by nerve cells and insulin secretion by pancreatic cells.

Membrane Protein Distribution

Membrane proteins and lipids are not symmetrically distributed; this contradicts the notion of equal distribution within the membrane structure.

Facilitated Diffusion Examples

Facilitated diffusion includes processes like ion channels and water channel proteins, whereas the electrogenic pump does not exemplify this process.

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Description

Prepare for your biology exam with this set of flashcards focused on key concepts related to the endosymbiotic theory, as well as characteristics shared by bacteria and archaea. Test your knowledge and reinforce your understanding of these fundamental biological principles.