Biology chapters 4-7

What are bacteria and archaea?

prokaryotic cells

active transport

a cell must expend energy to move a solute against its concentration gradient

The organelles and other structures of eukaryotic cells can be organized into four basic functional groups:

1) The nucleus and ribosomes carry out the genetic control of the cell 2) Organelles involved in the manufacture, distribution, and breakdown of molecules include the endoplasmic reticulum, golgi, apparatus, lysosomes, vacuoles, and peroxisomes 3) Mitochondria in all cells and chloroplasts in plant cells function in energy processing 4) Structural support, movement, and communication between cells are the functions of the cytoskeleton, plasma membrane, and plant cell wall

A cell used two mechanisms to move large molecules across membranes

1) exocytosis is used to export bulky molecules such as proteins or polysaccharides 2) endocytosis is used to take in large molecules

In order to start an exergonic reaction, a certain amount of energy must be absorbed by the reactants. This is called the energy of activation. Which of the following represents the energy of activation without enzymes?

A

Which of the following represents the energy of activation as modified by an enzyme?

B

This diagram represents osmosis of water across a semipermeable membrane. What could you do to level the solutions in the two sides of the U-tube on the right?

Add more solute to the left-hand side

Gap juntions

Allow ions and small molecules to flow from cell to cell

noncompetitive inhibitor

Alters an enzymes functions by changing its shape

Ribosomes

Are composed of ribosomal RNA and proteins and synthesize proteins according to directions from DNA

Hererotrophs

Are consumers that feed on plants or animals or decompose organic material

Imagine that you have planted bean seedlings and corn seedlings in an artificial soil and sealed them in an aquarium. The aquarium has plenty of light, nutrients, and water but is given volume of air. Based on your knowledge of photorespiration which of the following is most likely?

As the plants photosynthesis's the carbon dioxide levels will fall giving the C4 plants the advantage toward producing sugars

Animal cells synthesize and secrete an elaborate extracelluar matrix (ECM) which

Bonds tissue cells together, supports the plasma membrane and communicates with the cytoskeleton

light microscope

Can display living cells

What structures in the plant cell are not present in the animal cell?

Chloroplasts, central vacuole, cell wall, and plasmodesmata

Competitive inhIbitor

Competes with the substrate for the active site

Some prokaryotic and all eukaryotic cells use oxygen to harvest nevertheless from food molecules. In what form is that energy available to power cellular work?

D

Eukaryote cells

Distinguished by having a membrane-enclosed nucleus and many membrane-enclosed organelles that perform specific functions

When a photon of the correct energy is absorbed by a photo system, an electron is energized and transferred to a primary electron acceptor. This creates an electron hole. How are such missing electrons replaced?

Electrons from hydrogen made available by splitting water replace the missing electrons

potential energy

Energy stored in the location or structure of matter and includes chemical energy

All other forms of life have what?

Eukaryotic cells

This graph illustrates how an enzyme catalyzes a reaction in a biological system. From an energy standpoint, is this reaction endergonic or exergonic?

Exergonic

The figure represents an overview of the processes of cellular respiration. Which of the following correctly identifies the processes in the correct order?

Glycolysis, citric acid cycle, electron transport chain

In 1665, who used crude microscopes to examine a piece of bark from an oak tree and called them cells?

Hooke

Both cellular respiration and photosynthesis rely on electron transport chains embedded in membranes to produce ATP molecules. Which of the following correctly describes the difference between the two types of electron transport chains

In cellular respiration the electron source is the hydrogens in energy rich food and the final electron destination is oxygen

Cytoskeleton

Included microfilaments, intermediate filaments, and microtubules; their functions include: maintenance of cell shape, anchorage and movement of organelles, amoeboid movement, and muscle contraction

Chlorophyll

Is a light absorbing pigment in the chloroplasts that plays a central role in converting solar energy to chemical energy

Resolution

Is a measure of the clarity of an image. In other words it is the ability of an instrument to show two nearby objects as separate

Below is the summary equation for the process of photosynthesis

Is endergonic

Magnification

Is the increase in an objects image size compared with actual size

The microscopic size of most cells provides a

Large surface-to-volume ration

Vacuoles

Large vesicles that have a variety of functions

Leeuwenhoek used more refined lenses to describe..

Living cells from bllod, sperm, and ponds

Mitochondria

Organelles that carry out cellular respiration in nearly all eukaryotic cells

Rough ER

Produces membranes and ribosomes on its surface make membrane and secretory proteins

endergonic reaction

Require energy and yield products rich in potential energy

Cells that make a lot of proteins have a large number of what?

Ribosomes

anchoring junctions

River cells into strong tissues

Fat molecules store 9 kcal/g. There are about 454 g in a pound of fat, so one pound of fat stores about 4,000 kcal of energy. Based on the chart of energy consumption, which of the following would burn off a pound of fat?

Running 40 miles

Enzymes

Some membrane proteins are enzymes, enzymes may be grouped to carry out sequential reactions

In cellular respiration

Sugar is broken down to carbon dioxide and water and the cell captures some of the released energy to make ATP

Smooth ER

Synthesizes lipids and processes toxins

Photosynthesis

The conversion of light energy from the sun to the chemical energy of sugar molecules

The figure represents an overview of the entry pathways to cellular respiration when different macromolecules are digested for energy production. Why are none of the digestive products entering the electron transport chain directly?

The electron transport chain only receives electrons carried by reduced electron carrier molecules such as NADH.

Enzymes catalyze the many reactions in a cell. There are hundreds of different enzymes in a cell; each with a unique three dimensional shape. Why do cells have so many different enzymes?

The shape of the enzyme's active site generally fits a specific substrate.

Membranes organize cell activities. The proteins embedded in the membranes are essential to their function. These membrane proteins have properties that allow them to float in the membrane. Which of the following statements describes those properties?

The surface region of the protein in the interior of the membrane is mostly hydrophobic

Diffusion

The tendency of particles to spread out evenly in an available space

cell theory

all living things are composed of cells and all cells come from other cells

Transport proteins

allow specific ions or molecules to enter or exit the cell

attachment proteins

attach to the extracellular matrix and cytoskeleton, help support the membrane, can coordinate external and internal changes

tight junctions

bind cells very tightly together, forming a a leakproof sheet

All cells have

plasma membrane, DNA, ribosomes, and cytosol

kinetic energy

energy of motion

junction proteins

form intercellular junctions that attach adjacent cells

Peroxisomes

metabolic compartments that do not originate from the endomembrane system

fluid mosaic model

model that describes the arrangement and movement of the molecules that make up a cell membrane

plasma membrane

phospholipid bilayer with embedded proteins

Chloroplasts

photosynthesizing organelles of plants and algae

exergonic reactions

release energy

Glycoproteins

serve as ID tags, may be recognized by membrane proteins of other cells

Receptor proteins

signaling molecules bind to receptor proteins, receptor proteins relay the message by activating other molecules inside the cell

endosymbiont theory

states that mitochondria and chloroplasts were formerly small prokaryotes that began living within larger cells